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SSG troubleshoot and weird lm3900 behavior

SSG troubleshoot and weird lm3900 behavior

2013-04-09 by adematteo

Hey guys, I just put together the SSG and it's not working so i tried to switch out the lm3900's after giving the board some continuity testing and looking over the board briefly, i still need to do a lot more troubleshooting but what i wanted to ask about was this,
when i switched the lm3900's out it froze my system up as if there was a short in the power supply.I did some tests to see but couldn't find a short anywhere so i put the old ones back in and system powered back on fine so i switched them out with brand new ones i had and it cooked them within seconds of powering up.

Like i said i still have a bunch of leg work to do to figure out why it's not working but am confused that some of the lm3900's would create what appears to be a short and the others seem to have no effect ?

Thanks, Tony

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-09 by adematteo

I forgot to mention i'm getting all the correct power to the correct pins and am not finding any shorts between any of the pins.
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@...> wrote:
>
> Hey guys, I just put together the SSG and it's not working so i tried to switch out the lm3900's after giving the board some continuity testing and looking over the board briefly, i still need to do a lot more troubleshooting but what i wanted to ask about was this,
> when i switched the lm3900's out it froze my system up as if there was a short in the power supply.I did some tests to see but couldn't find a short anywhere so i put the old ones back in and system powered back on fine so i switched them out with brand new ones i had and it cooked them within seconds of powering up.
>
> Like i said i still have a bunch of leg work to do to figure out why it's not working but am confused that some of the lm3900's would create what appears to be a short and the others seem to have no effect ?
>
> Thanks, Tony
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-09 by cg_synth

There are two possible reasons 1) Are you putting them in backwards?
2) they aren't LM3900, despite whatever is written on them.
Show quoted textHide quoted text
>I forgot to mention i'm getting all the correct power to the correct pins
and am not finding any shorts between any of the pins.
>
>--- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@...> wrote:
>>
>> Hey guys, I just put together the SSG and it's not working so i tried to
switch out the lm3900's after giving the board some continuity testing and
looking over the board briefly, i still need to do a lot more
troubleshooting but what i wanted to ask about was this,
>> when i switched the lm3900's out it froze my system up as if there was a
short in the power supply.I did some tests to see but couldn't find a short
anywhere so i put the old ones back in and system powered back on fine so i
switched them out with brand new ones i had and it cooked them within
seconds of powering up.
>>
>> Like i said i still have a bunch of leg work to do to figure out why it's
not working but am confused that some of the lm3900's would create what
appears to be a short and the others seem to have no effect ?
>>
>> Thanks, Tony
>>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-09 by cg_synth

Also check you don't have your power rails swapped about.
If you have used CA3401 instead of a lm3900, and it's seeing 30V it will go
pop too, as they are only good for 15V rails, unlike the lm3900.
Show quoted textHide quoted text
>Hey guys, I just put together the SSG and it's not working so i tried to
switch out the lm3900's after giving the board some continuity testing and
looking over the board briefly, i still need to do a lot more
troubleshooting but what i wanted to ask about was this,
>when i switched the lm3900's out it froze my system up as if there was a
short in the power supply.I did some tests to see but couldn't find a short
anywhere so i put the old ones back in and system powered back on fine so i
switched them out with brand new ones i had and it cooked them within
seconds of powering up.
>
>Like i said i still have a bunch of leg work to do to figure out why it's
not working but am confused that some of the lm3900's would create what
appears to be a short and the others seem to have no effect ?
>
>Thanks, Tony
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-09 by adematteo

Thanks Ken, All the correct voltages are going to the correct pins (-15v to pin 7 +15v to pin 14) I may have put the 3900 that burned up in backwards ?

I checked all the component values and diode orientations this morning.I still have to go through and check continuity throughout the circuit.

I've noticed both sections outputs exhibit the same behavior which is a negative offset around -6v with nothing feeding the inputs.I checked pin 9 in the stepped section and if i feed a slow ramp and clock the sample input i get a varying voltage between -6 and -13v but always stays in that range.
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Also check you don't have your power rails swapped about.
> If you have used CA3401 instead of a lm3900, and it's seeing 30V it will go
> pop too, as they are only good for 15V rails, unlike the lm3900.
>
>
> >Hey guys, I just put together the SSG and it's not working so i tried to
> switch out the lm3900's after giving the board some continuity testing and
> looking over the board briefly, i still need to do a lot more
> troubleshooting but what i wanted to ask about was this,
> >when i switched the lm3900's out it froze my system up as if there was a
> short in the power supply.I did some tests to see but couldn't find a short
> anywhere so i put the old ones back in and system powered back on fine so i
> switched them out with brand new ones i had and it cooked them within
> seconds of powering up.
> >
> >Like i said i still have a bunch of leg work to do to figure out why it's
> not working but am confused that some of the lm3900's would create what
> appears to be a short and the others seem to have no effect ?
> >
> >Thanks, Tony
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-09 by adematteo

Ok, well my different manufacturer theory just went out the window.I popped in 2 more lm3900's from the same manufacturer of the ones i had in that didn't lock up my system and now the new ones are locking the system up.

I am measuring 330 ohm resistance between pin 3 (gnd ?) and pin 14(-v)
but only when the power is connected to the bus (unpowered) when i disconnect it from the bus it goes open.

This would leave me to believe that there's a short on my bus but all other modules work fine until i connect this one ? And i'm not finding any shorts when inspecting the bus.

This ones really throwing me for a loop,can't wait to figure out what i did.
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@...> wrote:
>
> Thanks Ken, All the correct voltages are going to the correct pins (-15v to pin 7 +15v to pin 14) I may have put the 3900 that burned up in backwards ?
>
> I checked all the component values and diode orientations this morning.I still have to go through and check continuity throughout the circuit.
>
> I've noticed both sections outputs exhibit the same behavior which is a negative offset around -6v with nothing feeding the inputs.I checked pin 9 in the stepped section and if i feed a slow ramp and clock the sample input i get a varying voltage between -6 and -13v but always stays in that range.
>
>
> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >
> > Also check you don't have your power rails swapped about.
> > If you have used CA3401 instead of a lm3900, and it's seeing 30V it will go
> > pop too, as they are only good for 15V rails, unlike the lm3900.
> >
> >
> > >Hey guys, I just put together the SSG and it's not working so i tried to
> > switch out the lm3900's after giving the board some continuity testing and
> > looking over the board briefly, i still need to do a lot more
> > troubleshooting but what i wanted to ask about was this,
> > >when i switched the lm3900's out it froze my system up as if there was a
> > short in the power supply.I did some tests to see but couldn't find a short
> > anywhere so i put the old ones back in and system powered back on fine so i
> > switched them out with brand new ones i had and it cooked them within
> > seconds of powering up.
> > >
> > >Like i said i still have a bunch of leg work to do to figure out why it's
> > not working but am confused that some of the lm3900's would create what
> > appears to be a short and the others seem to have no effect ?
> > >
> > >Thanks, Tony
> > >
> > >
> > >
> > >------------------------------------
> > >
> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > >Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > _______________________________________________________________________
> > Ken Stone sasami@ otherunicorn@
> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> >
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-09 by cg_synth

I have no idea why you are seeing what you are seeing. It defies logic.
All I can do is give you some trouble shooting tips.
Use your eyes (not a meter) to inspect the board. Every track, every part.
Do it with the board rotated so you are looking at it afresh. If ANYTHING
looks slightly dodgy, fix it. So often it is the slightly dodgy solder
joint/component that is the problem.
Hold the board to the light, and see if there are any unfilled holes. You
may find a link or part is missing.
Ken
Show quoted textHide quoted text
>Ok, well my different manufacturer theory just went out the window.I popped
in 2 more lm3900's from the same manufacturer of the ones i had in that
didn't lock up my system and now the new ones are locking the system up.
>
>I am measuring 330 ohm resistance between pin 3 (gnd ?) and pin 14(-v)
>but only when the power is connected to the bus (unpowered) when i
disconnect it from the bus it goes open.
>
>This would leave me to believe that there's a short on my bus but all other
modules work fine until i connect this one ? And i'm not finding any shorts
when inspecting the bus.
>
>This ones really throwing me for a loop,can't wait to figure out what i did.
>
>--- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@...> wrote:
>>
>> Thanks Ken, All the correct voltages are going to the correct pins (-15v
to pin 7 +15v to pin 14) I may have put the 3900 that burned up in backwards ?
>>
>> I checked all the component values and diode orientations this morning.I
still have to go through and check continuity throughout the circuit.
>>
>> I've noticed both sections outputs exhibit the same behavior which is a
negative offset around -6v with nothing feeding the inputs.I checked pin 9
in the stepped section and if i feed a slow ramp and clock the sample input
i get a varying voltage between -6 and -13v but always stays in that range.
>>
>>
>> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> >
>> > Also check you don't have your power rails swapped about.
>> > If you have used CA3401 instead of a lm3900, and it's seeing 30V it will go
>> > pop too, as they are only good for 15V rails, unlike the lm3900.
>> >
>> >
>> > >Hey guys, I just put together the SSG and it's not working so i tried to
>> > switch out the lm3900's after giving the board some continuity testing and
>> > looking over the board briefly, i still need to do a lot more
>> > troubleshooting but what i wanted to ask about was this,
>> > >when i switched the lm3900's out it froze my system up as if there was a
>> > short in the power supply.I did some tests to see but couldn't find a short
>> > anywhere so i put the old ones back in and system powered back on fine so i
>> > switched them out with brand new ones i had and it cooked them within
>> > seconds of powering up.
>> > >
>> > >Like i said i still have a bunch of leg work to do to figure out why it's
>> > not working but am confused that some of the lm3900's would create what
>> > appears to be a short and the others seem to have no effect ?
>> > >
>> > >Thanks, Tony
>> > >
>> > >
>> > >
>> > >------------------------------------
>> > >
>> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> > >Yahoo! Groups Links
>> > >
>> > >
>> > >
>> > >
>> > _______________________________________________________________________
>> > Ken Stone sasami@ otherunicorn@
>> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> > Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>> >
>>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-09 by Richarius Molindarius

Use a well lit magnified lamp. Especially for that board. Hard to find
small trace breaks and bad solder joints.


[Non-text portions of this message have been removed]

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-10 by adematteo

Will do.Thanks guys!
I'll report back when i get this working.
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, Richarius Molindarius <richmolindarius@...> wrote:
>
> Use a well lit magnified lamp. Especially for that board. Hard to find
> small trace breaks and bad solder joints.
>
>
> [Non-text portions of this message have been removed]
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-10 by cg_synth

Been thinkng about this - The problem may also be caused by putting a
voltage on the input pins, which are designed for current, not voltage.
Check nothing is shorted to them. Check your resistor values. Maye sure you
haven't installed 15 ohms instead of 1M.

Ken
Show quoted textHide quoted text
>Will do.Thanks guys!
>I'll report back when i get this working.
>
>--- In cgs_synth@yahoogroups.com, Richarius Molindarius
<richmolindarius@...> wrote:
>>
>> Use a well lit magnified lamp. Especially for that board. Hard to find
>> small trace breaks and bad solder joints.
>>
>>
>> [Non-text portions of this message have been removed]
>>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-12 by adematteo

Thanks again Ken, and Rich for all the helpful suggestions.
I've triple checked component values at this point,replaced trannies,ic's,gone over continuity testing and visually inspected the board under a magnifying lens with no luck.

There has to be a short or something that i am just not seeing because i'm getting inconsistent results when i plug it in every time i make a change.I fried another lm3900 in the smooth section only this time it took a few minutes.I've been able to get a slewed/smoothed signal to pass but no control over the hold or rate, i've gotten a steady tone from plugging the cycle into the in of the smooth section but again no control to change the pitch and now i'm back to were i started with no effect and a strong negative voltage on the outputs ?

I'm gonna take a little break but at this point i'm seriously considering a do over.

Thanks again guys i really appreciate you taking the time to offer your time and experience !
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Been thinkng about this - The problem may also be caused by putting a
> voltage on the input pins, which are designed for current, not voltage.
> Check nothing is shorted to them. Check your resistor values. Maye sure you
> haven't installed 15 ohms instead of 1M.
>
> Ken
>
> >Will do.Thanks guys!
> >I'll report back when i get this working.
> >
> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> <richmolindarius@> wrote:
> >>
> >> Use a well lit magnified lamp. Especially for that board. Hard to find
> >> small trace breaks and bad solder joints.
> >>
> >>
> >> [Non-text portions of this message have been removed]
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-12 by cg_synth

Seriously, chip frying is indication of serious power routing issues.

With the chips OUT, read the voltages on each pin of the socket, then list
them here.

Ken
Show quoted textHide quoted text
>Thanks again Ken, and Rich for all the helpful suggestions.
>I've triple checked component values at this point,replaced
trannies,ic's,gone over continuity testing and visually inspected the board
under a magnifying lens with no luck.
>
>There has to be a short or something that i am just not seeing because i'm
getting inconsistent results when i plug it in every time i make a change.I
fried another lm3900 in the smooth section only this time it took a few
minutes.I've been able to get a slewed/smoothed signal to pass but no
control over the hold or rate, i've gotten a steady tone from plugging the
cycle into the in of the smooth section but again no control to change the
pitch and now i'm back to were i started with no effect and a strong
negative voltage on the outputs ?
>
>I'm gonna take a little break but at this point i'm seriously considering a
do over.
>
>Thanks again guys i really appreciate you taking the time to offer your
time and experience !
>
>--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>>
>> Been thinkng about this - The problem may also be caused by putting a
>> voltage on the input pins, which are designed for current, not voltage.
>> Check nothing is shorted to them. Check your resistor values. Maye sure you
>> haven't installed 15 ohms instead of 1M.
>>
>> Ken
>>
>> >Will do.Thanks guys!
>> >I'll report back when i get this working.
>> >
>> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
>> <richmolindarius@> wrote:
>> >>
>> >> Use a well lit magnified lamp. Especially for that board. Hard to find
>> >> small trace breaks and bad solder joints.
>> >>
>> >>
>> >> [Non-text portions of this message have been removed]
>> >>
>> >
>> >
>> >
>> >
>> >------------------------------------
>> >
>> >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> >Yahoo! Groups Links
>> >
>> >
>> >
>> >
>> _______________________________________________________________________
>> Ken Stone sasami@... otherunicorn@...
>> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-12 by adematteo

So all the voltages read the same on both chips except for pin 13 which i make a note of :

1) +13.54 14) +15
2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
3) -9.23 12) +13
4) -14.35 11) -.115
5) +11.13 10) -.112
6) -0.113 9) 0
7) -15 8)-.010
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Seriously, chip frying is indication of serious power routing issues.
>
> With the chips OUT, read the voltages on each pin of the socket, then list
> them here.
>
> Ken
>
> >Thanks again Ken, and Rich for all the helpful suggestions.
> >I've triple checked component values at this point,replaced
> trannies,ic's,gone over continuity testing and visually inspected the board
> under a magnifying lens with no luck.
> >
> >There has to be a short or something that i am just not seeing because i'm
> getting inconsistent results when i plug it in every time i make a change.I
> fried another lm3900 in the smooth section only this time it took a few
> minutes.I've been able to get a slewed/smoothed signal to pass but no
> control over the hold or rate, i've gotten a steady tone from plugging the
> cycle into the in of the smooth section but again no control to change the
> pitch and now i'm back to were i started with no effect and a strong
> negative voltage on the outputs ?
> >
> >I'm gonna take a little break but at this point i'm seriously considering a
> do over.
> >
> >Thanks again guys i really appreciate you taking the time to offer your
> time and experience !
> >
> >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >>
> >> Been thinkng about this - The problem may also be caused by putting a
> >> voltage on the input pins, which are designed for current, not voltage.
> >> Check nothing is shorted to them. Check your resistor values. Maye sure you
> >> haven't installed 15 ohms instead of 1M.
> >>
> >> Ken
> >>
> >> >Will do.Thanks guys!
> >> >I'll report back when i get this working.
> >> >
> >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> >> <richmolindarius@> wrote:
> >> >>
> >> >> Use a well lit magnified lamp. Especially for that board. Hard to find
> >> >> small trace breaks and bad solder joints.
> >> >>
> >> >>
> >> >> [Non-text portions of this message have been removed]
> >> >>
> >> >
> >> >
> >> >
> >> >
> >> >------------------------------------
> >> >
> >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> >Yahoo! Groups Links
> >> >
> >> >
> >> >
> >> >
> >> _______________________________________________________________________
> >> Ken Stone sasami@ otherunicorn@
> >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-12 by adematteo

Sorry, that came out as a big garbled mess.


1) +13.54
2) 0
3) -9.23
4) -14.35
5) +11.13
6) -0.113
7) -15
8) -.010
9) 0
10) -.112
11) -.115
12) +13
13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
14) +15
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@...> wrote:
>
> So all the voltages read the same on both chips except for pin 13 which i make a note of :
>
> 1) +13.54 14) +15
> 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
> 3) -9.23 12) +13
> 4) -14.35 11) -.115
> 5) +11.13 10) -.112
> 6) -0.113 9) 0
> 7) -15 8)-.010
>
> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >
> > Seriously, chip frying is indication of serious power routing issues.
> >
> > With the chips OUT, read the voltages on each pin of the socket, then list
> > them here.
> >
> > Ken
> >
> > >Thanks again Ken, and Rich for all the helpful suggestions.
> > >I've triple checked component values at this point,replaced
> > trannies,ic's,gone over continuity testing and visually inspected the board
> > under a magnifying lens with no luck.
> > >
> > >There has to be a short or something that i am just not seeing because i'm
> > getting inconsistent results when i plug it in every time i make a change.I
> > fried another lm3900 in the smooth section only this time it took a few
> > minutes.I've been able to get a slewed/smoothed signal to pass but no
> > control over the hold or rate, i've gotten a steady tone from plugging the
> > cycle into the in of the smooth section but again no control to change the
> > pitch and now i'm back to were i started with no effect and a strong
> > negative voltage on the outputs ?
> > >
> > >I'm gonna take a little break but at this point i'm seriously considering a
> > do over.
> > >
> > >Thanks again guys i really appreciate you taking the time to offer your
> > time and experience !
> > >
> > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > >>
> > >> Been thinkng about this - The problem may also be caused by putting a
> > >> voltage on the input pins, which are designed for current, not voltage.
> > >> Check nothing is shorted to them. Check your resistor values. Maye sure you
> > >> haven't installed 15 ohms instead of 1M.
> > >>
> > >> Ken
> > >>
> > >> >Will do.Thanks guys!
> > >> >I'll report back when i get this working.
> > >> >
> > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> > >> <richmolindarius@> wrote:
> > >> >>
> > >> >> Use a well lit magnified lamp. Especially for that board. Hard to find
> > >> >> small trace breaks and bad solder joints.
> > >> >>
> > >> >>
> > >> >> [Non-text portions of this message have been removed]
> > >> >>
> > >> >
> > >> >
> > >> >
> > >> >
> > >> >------------------------------------
> > >> >
> > >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > >> >Yahoo! Groups Links
> > >> >
> > >> >
> > >> >
> > >> >
> > >> _______________________________________________________________________
> > >> Ken Stone sasami@ otherunicorn@
> > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > >> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> > >>
> > >
> > >
> > >
> > >
> > >------------------------------------
> > >
> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > >Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > _______________________________________________________________________
> > Ken Stone sasami@ otherunicorn@
> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> >
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-13 by cg_synth

Okay, those voltages were more or less what I got.
Now take a 1k resistor and connect one end to -15. Connect the other end of
the 1k resistor to each input pin in turn, and read the voltages. If all is
well, they will read around -14.5 to -15 volts. If any read much higher than
that, that is probably where the problem is.


Below are what I got on those pins with chips IN.
Show quoted textHide quoted text
>1) -14.3
>2) -14.3
>3) -14.3
>4) -14.5
>5) -14.8 (Smooth) +14.8 (Stepped) (this will depend on what the module is
doing!)
>6) -14.5
>7) -15
>8) -14.9
>9) +14.2
>10) 0, -0.2 (Stepped)
>11) -14.5
>12) -14.5
>13) -14.5
>14) +15

Other than that, it would be high-resolution pic time.

Ken
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-13 by adematteo

Well, i did these tests and everything checked out except for pin 3 on both sides i was getting -9.4v.

Now here's the kicker, the smooth section all of a sudden started working because as i was monitoring it i pressed on the trimmer for the stepped section, but the stepped section is still not working.
I tried flexing the board to get it to stop working again but can't.

So, i'm assuming there's an intermittent short or fragile trace that i'm not catching ?
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Okay, those voltages were more or less what I got.
> Now take a 1k resistor and connect one end to -15. Connect the other end of
> the 1k resistor to each input pin in turn, and read the voltages. If all is
> well, they will read around -14.5 to -15 volts. If any read much higher than
> that, that is probably where the problem is.
>
>
> Below are what I got on those pins with chips IN.
>
> >1) -14.3
> >2) -14.3
> >3) -14.3
> >4) -14.5
> >5) -14.8 (Smooth) +14.8 (Stepped) (this will depend on what the module is
> doing!)
> >6) -14.5
> >7) -15
> >8) -14.9
> >9) +14.2
> >10) 0, -0.2 (Stepped)
> >11) -14.5
> >12) -14.5
> >13) -14.5
> >14) +15
>
> Other than that, it would be high-resolution pic time.
>
> Ken
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-13 by Dave Kendall

On 13 Apr 2013, at 18:24, adematteo wrote:
Show quoted textHide quoted text
> So, i'm assuming there's an intermittent short or fragile trace that
> i'm not catching ?

FWIW, I've been caught by them before - once a *very* tiny sliver of
solder bridging things it shouldn't, and another time an almost
invisible etching fault. The solder sliver had fallen from a solder
sucker when tweaking/subbing components, and had lodged somewhere
awkward.
Back when my eyes were pretty good, I still didn't spot either until a
magnifying glass was used.

Good luck - hope you find it.

cheers,
Dave


>
> --- In cgs_synth@yahoogroups.com, sasami@... wrote:
> >
> > Okay, those voltages were more or less what I got.
> > Now take a 1k resistor and connect one end to -15. Connect the
> other end of
> > the 1k resistor to each input pin in turn, and read the voltages.
> If all is
> > well, they will read around -14.5 to -15 volts. If any read much
> higher than
> > that, that is probably where the problem is.
> >
> >
> > Below are what I got on those pins with chips IN.
> >
> > >1) -14.3
> > >2) -14.3
> > >3) -14.3
> > >4) -14.5
> > >5) -14.8 (Smooth) +14.8 (Stepped) (this will depend on what the
> module is
> > doing!)
> > >6) -14.5
> > >7) -15
> > >8) -14.9
> > >9) +14.2
> > >10) 0, -0.2 (Stepped)
> > >11) -14.5
> > >12) -14.5
> > >13) -14.5
> > >14) +15
> >
> > Other than that, it would be high-resolution pic time.
> >
> > Ken
> > __________________________________________________________
> > Ken Stone sasami@... otherunicorn@...
> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > Australian Miniature Horses & Ponies
> <http://www.blaze.net.au/~sasami/>
> >
>
>
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-13 by adematteo

Thanks Dave, this ones been making me crazy !

So, i took my son to his soccer game and got back and fired it up and now both sections are working after popping another 3900 in the stepped section.So either i have a whole bunch of bad luck w/ the 3 different batches of 3900's i have, or as i really suspect i have some funky stuff electrically going on.

So for now i guess i'll just rock this thing out and keep my fingers crossed.

Thanks gain Ken for being so generous with your time i really appreciate it !
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, Dave Kendall <davekendall@...> wrote:
>
>
> On 13 Apr 2013, at 18:24, adematteo wrote:
> > So, i'm assuming there's an intermittent short or fragile trace that
> > i'm not catching ?
>
> FWIW, I've been caught by them before - once a *very* tiny sliver of
> solder bridging things it shouldn't, and another time an almost
> invisible etching fault. The solder sliver had fallen from a solder
> sucker when tweaking/subbing components, and had lodged somewhere
> awkward.
> Back when my eyes were pretty good, I still didn't spot either until a
> magnifying glass was used.
>
> Good luck - hope you find it.
>
> cheers,
> Dave
>
>
> >
> > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > >
> > > Okay, those voltages were more or less what I got.
> > > Now take a 1k resistor and connect one end to -15. Connect the
> > other end of
> > > the 1k resistor to each input pin in turn, and read the voltages.
> > If all is
> > > well, they will read around -14.5 to -15 volts. If any read much
> > higher than
> > > that, that is probably where the problem is.
> > >
> > >
> > > Below are what I got on those pins with chips IN.
> > >
> > > >1) -14.3
> > > >2) -14.3
> > > >3) -14.3
> > > >4) -14.5
> > > >5) -14.8 (Smooth) +14.8 (Stepped) (this will depend on what the
> > module is
> > > doing!)
> > > >6) -14.5
> > > >7) -15
> > > >8) -14.9
> > > >9) +14.2
> > > >10) 0, -0.2 (Stepped)
> > > >11) -14.5
> > > >12) -14.5
> > > >13) -14.5
> > > >14) +15
> > >
> > > Other than that, it would be high-resolution pic time.
> > >
> > > Ken
> > > __________________________________________________________
> > > Ken Stone sasami@ otherunicorn@
> > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > > Australian Miniature Horses & Ponies
> > <http://www.blaze.net.au/~sasami/>
> > >
> >
> >
> >
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-21 by Sean

Finished building an SSG last night and am having similar issues. Keep popping LM3900s. They go fast and extremely hot! Checked traces (I'll check again) but haven't troubleshooted extensively yet. btw, I used J201 (not J201A) and 50v 10uf Electrolytic (not 25v) and somewhat concerned about the 100pf cap (looks like mine says 101. Should be correct). I'll get back in touch.

Thanks, Sean
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Okay, those voltages were more or less what I got.
> Now take a 1k resistor and connect one end to -15. Connect the other end of
> the 1k resistor to each input pin in turn, and read the voltages. If all is
> well, they will read around -14.5 to -15 volts. If any read much higher than
> that, that is probably where the problem is.
>
>
> Below are what I got on those pins with chips IN.
>
> >1) -14.3
> >2) -14.3
> >3) -14.3
> >4) -14.5
> >5) -14.8 (Smooth) +14.8 (Stepped) (this will depend on what the module is
> doing!)
> >6) -14.5
> >7) -15
> >8) -14.9
> >9) +14.2
> >10) 0, -0.2 (Stepped)
> >11) -14.5
> >12) -14.5
> >13) -14.5
> >14) +15
>
> Other than that, it would be high-resolution pic time.
>
> Ken
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-21 by Sean

Been testing my voltages (with blown LM3900s removed) btw, pin 9 is getting burns on IC socket.

1) +7.50
2) 0
3) -7.41
4) -14.01
5) +3.59
6) -0.06
7) -14.87
8) -0.01
9) 0
10) -0.10
11) -0.06
12) +8.06
13) -3.34 (stepped), +5.82 (smooth)
14) +14.86

Strange voltages I'm getting.
-Sean
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@...> wrote:
>
> Sorry, that came out as a big garbled mess.
>
>
> 1) +13.54
> 2) 0
> 3) -9.23
> 4) -14.35
> 5) +11.13
> 6) -0.113
> 7) -15
> 8) -.010
> 9) 0
> 10) -.112
> 11) -.115
> 12) +13
> 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
> 14) +15
>
> --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >
> > So all the voltages read the same on both chips except for pin 13 which i make a note of :
> >
> > 1) +13.54 14) +15
> > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
> > 3) -9.23 12) +13
> > 4) -14.35 11) -.115
> > 5) +11.13 10) -.112
> > 6) -0.113 9) 0
> > 7) -15 8)-.010
> >
> > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > >
> > > Seriously, chip frying is indication of serious power routing issues.
> > >
> > > With the chips OUT, read the voltages on each pin of the socket, then list
> > > them here.
> > >
> > > Ken
> > >
> > > >Thanks again Ken, and Rich for all the helpful suggestions.
> > > >I've triple checked component values at this point,replaced
> > > trannies,ic's,gone over continuity testing and visually inspected the board
> > > under a magnifying lens with no luck.
> > > >
> > > >There has to be a short or something that i am just not seeing because i'm
> > > getting inconsistent results when i plug it in every time i make a change.I
> > > fried another lm3900 in the smooth section only this time it took a few
> > > minutes.I've been able to get a slewed/smoothed signal to pass but no
> > > control over the hold or rate, i've gotten a steady tone from plugging the
> > > cycle into the in of the smooth section but again no control to change the
> > > pitch and now i'm back to were i started with no effect and a strong
> > > negative voltage on the outputs ?
> > > >
> > > >I'm gonna take a little break but at this point i'm seriously considering a
> > > do over.
> > > >
> > > >Thanks again guys i really appreciate you taking the time to offer your
> > > time and experience !
> > > >
> > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > > >>
> > > >> Been thinkng about this - The problem may also be caused by putting a
> > > >> voltage on the input pins, which are designed for current, not voltage.
> > > >> Check nothing is shorted to them. Check your resistor values. Maye sure you
> > > >> haven't installed 15 ohms instead of 1M.
> > > >>
> > > >> Ken
> > > >>
> > > >> >Will do.Thanks guys!
> > > >> >I'll report back when i get this working.
> > > >> >
> > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> > > >> <richmolindarius@> wrote:
> > > >> >>
> > > >> >> Use a well lit magnified lamp. Especially for that board. Hard to find
> > > >> >> small trace breaks and bad solder joints.
> > > >> >>
> > > >> >>
> > > >> >> [Non-text portions of this message have been removed]
> > > >> >>
> > > >> >
> > > >> >
> > > >> >
> > > >> >
> > > >> >------------------------------------
> > > >> >
> > > >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > > >> >Yahoo! Groups Links
> > > >> >
> > > >> >
> > > >> >
> > > >> >
> > > >> _______________________________________________________________________
> > > >> Ken Stone sasami@ otherunicorn@
> > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > > >> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> > > >>
> > > >
> > > >
> > > >
> > > >
> > > >------------------------------------
> > > >
> > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > > >Yahoo! Groups Links
> > > >
> > > >
> > > >
> > > >
> > > _______________________________________________________________________
> > > Ken Stone sasami@ otherunicorn@
> > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > > Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> > >
> >
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-21 by cg_synth

--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@...> wrote:
Show quoted textHide quoted text
>
> Finished building an SSG last night and am having similar issues. Keep popping LM3900s. They go fast and extremely hot! Checked traces (I'll check again) but haven't troubleshooted extensively yet. btw, I used J201 (not J201A) and 50v 10uf Electrolytic (not 25v) and somewhat concerned about the 100pf cap (looks like mine says 101. Should be correct). I'll get back in touch.

101 is 100pF
50V caps are fine. Greater voltage is always okay.
J201 is correct. I think the "A" was a typo.
NOTHING should get hot, or even mildly warm.

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-22 by cg_synth

pin 9 should be connected only to a 1n capacitor. Pad T is not used. There should be no current flow through it. Find out what pin 9 of the socket is short circuited to.
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@...> wrote:
>
> Been testing my voltages (with blown LM3900s removed) btw, pin 9 is getting burns on IC socket.
>
> 1) +7.50
> 2) 0
> 3) -7.41
> 4) -14.01
> 5) +3.59
> 6) -0.06
> 7) -14.87
> 8) -0.01
> 9) 0
> 10) -0.10
> 11) -0.06
> 12) +8.06
> 13) -3.34 (stepped), +5.82 (smooth)
> 14) +14.86
>
> Strange voltages I'm getting.
> -Sean
>
> --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >
> > Sorry, that came out as a big garbled mess.
> >
> >
> > 1) +13.54
> > 2) 0
> > 3) -9.23
> > 4) -14.35
> > 5) +11.13
> > 6) -0.113
> > 7) -15
> > 8) -.010
> > 9) 0
> > 10) -.112
> > 11) -.115
> > 12) +13
> > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
> > 14) +15
> >
> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> > >
> > > So all the voltages read the same on both chips except for pin 13 which i make a note of :
> > >
> > > 1) +13.54 14) +15
> > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
> > > 3) -9.23 12) +13
> > > 4) -14.35 11) -.115
> > > 5) +11.13 10) -.112
> > > 6) -0.113 9) 0
> > > 7) -15 8)-.010
> > >
> > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > > >
> > > > Seriously, chip frying is indication of serious power routing issues.
> > > >
> > > > With the chips OUT, read the voltages on each pin of the socket, then list
> > > > them here.
> > > >
> > > > Ken
> > > >
> > > > >Thanks again Ken, and Rich for all the helpful suggestions.
> > > > >I've triple checked component values at this point,replaced
> > > > trannies,ic's,gone over continuity testing and visually inspected the board
> > > > under a magnifying lens with no luck.
> > > > >
> > > > >There has to be a short or something that i am just not seeing because i'm
> > > > getting inconsistent results when i plug it in every time i make a change.I
> > > > fried another lm3900 in the smooth section only this time it took a few
> > > > minutes.I've been able to get a slewed/smoothed signal to pass but no
> > > > control over the hold or rate, i've gotten a steady tone from plugging the
> > > > cycle into the in of the smooth section but again no control to change the
> > > > pitch and now i'm back to were i started with no effect and a strong
> > > > negative voltage on the outputs ?
> > > > >
> > > > >I'm gonna take a little break but at this point i'm seriously considering a
> > > > do over.
> > > > >
> > > > >Thanks again guys i really appreciate you taking the time to offer your
> > > > time and experience !
> > > > >
> > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > > > >>
> > > > >> Been thinkng about this - The problem may also be caused by putting a
> > > > >> voltage on the input pins, which are designed for current, not voltage.
> > > > >> Check nothing is shorted to them. Check your resistor values. Maye sure you
> > > > >> haven't installed 15 ohms instead of 1M.
> > > > >>
> > > > >> Ken
> > > > >>
> > > > >> >Will do.Thanks guys!
> > > > >> >I'll report back when i get this working.
> > > > >> >
> > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> > > > >> <richmolindarius@> wrote:
> > > > >> >>
> > > > >> >> Use a well lit magnified lamp. Especially for that board. Hard to find
> > > > >> >> small trace breaks and bad solder joints.
> > > > >> >>
> > > > >> >>
> > > > >> >> [Non-text portions of this message have been removed]
> > > > >> >>
> > > > >> >
> > > > >> >
> > > > >> >
> > > > >> >
> > > > >> >------------------------------------
> > > > >> >
> > > > >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > > > >> >Yahoo! Groups Links
> > > > >> >
> > > > >> >
> > > > >> >
> > > > >> >
> > > > >> _______________________________________________________________________
> > > > >> Ken Stone sasami@ otherunicorn@
> > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > > > >> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> > > > >>
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >------------------------------------
> > > > >
> > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > > > >Yahoo! Groups Links
> > > > >
> > > > >
> > > > >
> > > > >
> > > > _______________________________________________________________________
> > > > Ken Stone sasami@ otherunicorn@
> > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > > > Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> > > >
> > >
> >
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-22 by Sean

Yup, only connected to 1n cap and not using pad T. No shorting when chip is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've checked solder joints and traces many times over. I can't help but think it's something else.. maybe a weird transistor or cap or mislabel resistor here? btw, same behavior on both LM3900s... extreme heat. Ouch.
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@...> wrote:
>
> pin 9 should be connected only to a 1n capacitor. Pad T is not used. There should be no current flow through it. Find out what pin 9 of the socket is short circuited to.
>
> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >
> > Been testing my voltages (with blown LM3900s removed) btw, pin 9 is getting burns on IC socket.
> >
> > 1) +7.50
> > 2) 0
> > 3) -7.41
> > 4) -14.01
> > 5) +3.59
> > 6) -0.06
> > 7) -14.87
> > 8) -0.01
> > 9) 0
> > 10) -0.10
> > 11) -0.06
> > 12) +8.06
> > 13) -3.34 (stepped), +5.82 (smooth)
> > 14) +14.86
> >
> > Strange voltages I'm getting.
> > -Sean
> >
> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> > >
> > > Sorry, that came out as a big garbled mess.
> > >
> > >
> > > 1) +13.54
> > > 2) 0
> > > 3) -9.23
> > > 4) -14.35
> > > 5) +11.13
> > > 6) -0.113
> > > 7) -15
> > > 8) -.010
> > > 9) 0
> > > 10) -.112
> > > 11) -.115
> > > 12) +13
> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
> > > 14) +15
> > >
> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> > > >
> > > > So all the voltages read the same on both chips except for pin 13 which i make a note of :
> > > >
> > > > 1) +13.54 14) +15
> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
> > > > 3) -9.23 12) +13
> > > > 4) -14.35 11) -.115
> > > > 5) +11.13 10) -.112
> > > > 6) -0.113 9) 0
> > > > 7) -15 8)-.010
> > > >
> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > > > >
> > > > > Seriously, chip frying is indication of serious power routing issues.
> > > > >
> > > > > With the chips OUT, read the voltages on each pin of the socket, then list
> > > > > them here.
> > > > >
> > > > > Ken
> > > > >
> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
> > > > > >I've triple checked component values at this point,replaced
> > > > > trannies,ic's,gone over continuity testing and visually inspected the board
> > > > > under a magnifying lens with no luck.
> > > > > >
> > > > > >There has to be a short or something that i am just not seeing because i'm
> > > > > getting inconsistent results when i plug it in every time i make a change.I
> > > > > fried another lm3900 in the smooth section only this time it took a few
> > > > > minutes.I've been able to get a slewed/smoothed signal to pass but no
> > > > > control over the hold or rate, i've gotten a steady tone from plugging the
> > > > > cycle into the in of the smooth section but again no control to change the
> > > > > pitch and now i'm back to were i started with no effect and a strong
> > > > > negative voltage on the outputs ?
> > > > > >
> > > > > >I'm gonna take a little break but at this point i'm seriously considering a
> > > > > do over.
> > > > > >
> > > > > >Thanks again guys i really appreciate you taking the time to offer your
> > > > > time and experience !
> > > > > >
> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > > > > >>
> > > > > >> Been thinkng about this - The problem may also be caused by putting a
> > > > > >> voltage on the input pins, which are designed for current, not voltage.
> > > > > >> Check nothing is shorted to them. Check your resistor values. Maye sure you
> > > > > >> haven't installed 15 ohms instead of 1M.
> > > > > >>
> > > > > >> Ken
> > > > > >>
> > > > > >> >Will do.Thanks guys!
> > > > > >> >I'll report back when i get this working.
> > > > > >> >
> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> > > > > >> <richmolindarius@> wrote:
> > > > > >> >>
> > > > > >> >> Use a well lit magnified lamp. Especially for that board. Hard to find
> > > > > >> >> small trace breaks and bad solder joints.
> > > > > >> >>
> > > > > >> >>
> > > > > >> >> [Non-text portions of this message have been removed]
> > > > > >> >>
> > > > > >> >
> > > > > >> >
> > > > > >> >
> > > > > >> >
> > > > > >> >------------------------------------
> > > > > >> >
> > > > > >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > > > > >> >Yahoo! Groups Links
> > > > > >> >
> > > > > >> >
> > > > > >> >
> > > > > >> >
> > > > > >> _______________________________________________________________________
> > > > > >> Ken Stone sasami@ otherunicorn@
> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > > > > >> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> > > > > >>
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >------------------------------------
> > > > > >
> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > > > > >Yahoo! Groups Links
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > _______________________________________________________________________
> > > > > Ken Stone sasami@ otherunicorn@
> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > > > > Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> > > > >
> > > >
> > >
> >
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-22 by cg_synth

Take some high res photos - IN FOCUS - of both sides so we can look at it.
Ken
Show quoted textHide quoted text
>Yup, only connected to 1n cap and not using pad T. No shorting when chip
is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
checked solder joints and traces many times over. I can't help but think
it's something else.. maybe a weird transistor or cap or mislabel resistor
here? btw, same behavior on both LM3900s... extreme heat. Ouch.
>
>--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@...> wrote:
>>
>> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
There should be no current flow through it. Find out what pin 9 of the
socket is short circuited to.
>>
>> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
>> >
>> > Been testing my voltages (with blown LM3900s removed) btw, pin 9 is
getting burns on IC socket.
>> >
>> > 1) +7.50
>> > 2) 0
>> > 3) -7.41
>> > 4) -14.01
>> > 5) +3.59
>> > 6) -0.06
>> > 7) -14.87
>> > 8) -0.01
>> > 9) 0
>> > 10) -0.10
>> > 11) -0.06
>> > 12) +8.06
>> > 13) -3.34 (stepped), +5.82 (smooth)
>> > 14) +14.86
>> >
>> > Strange voltages I'm getting.
>> > -Sean
>> >
>> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
>> > >
>> > > Sorry, that came out as a big garbled mess.
>> > >
>> > >
>> > > 1) +13.54
>> > > 2) 0
>> > > 3) -9.23
>> > > 4) -14.35
>> > > 5) +11.13
>> > > 6) -0.113
>> > > 7) -15
>> > > 8) -.010
>> > > 9) 0
>> > > 10) -.112
>> > > 11) -.115
>> > > 12) +13
>> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
>> > > 14) +15
>> > >
>> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
>> > > >
>> > > > So all the voltages read the same on both chips except for pin 13
which i make a note of :
>> > > >
>> > > > 1) +13.54 14) +15
>> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
>> > > > 3) -9.23 12) +13
>> > > > 4) -14.35 11) -.115
>> > > > 5) +11.13 10) -.112
>> > > > 6) -0.113 9) 0
>> > > > 7) -15 8)-.010
>> > > >
>> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> > > > >
>> > > > > Seriously, chip frying is indication of serious power routing issues.
>> > > > >
>> > > > > With the chips OUT, read the voltages on each pin of the socket,
then list
>> > > > > them here.
>> > > > >
>> > > > > Ken
>> > > > >
>> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
>> > > > > >I've triple checked component values at this point,replaced
>> > > > > trannies,ic's,gone over continuity testing and visually inspected
the board
>> > > > > under a magnifying lens with no luck.
>> > > > > >
>> > > > > >There has to be a short or something that i am just not seeing
because i'm
>> > > > > getting inconsistent results when i plug it in every time i make
a change.I
>> > > > > fried another lm3900 in the smooth section only this time it took
a few
>> > > > > minutes.I've been able to get a slewed/smoothed signal to pass but no
>> > > > > control over the hold or rate, i've gotten a steady tone from
plugging the
>> > > > > cycle into the in of the smooth section but again no control to
change the
>> > > > > pitch and now i'm back to were i started with no effect and a strong
>> > > > > negative voltage on the outputs ?
>> > > > > >
>> > > > > >I'm gonna take a little break but at this point i'm seriously
considering a
>> > > > > do over.
>> > > > > >
>> > > > > >Thanks again guys i really appreciate you taking the time to
offer your
>> > > > > time and experience !
>> > > > > >
>> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> > > > > >>
>> > > > > >> Been thinkng about this - The problem may also be caused by
putting a
>> > > > > >> voltage on the input pins, which are designed for current, not
voltage.
>> > > > > >> Check nothing is shorted to them. Check your resistor values.
Maye sure you
>> > > > > >> haven't installed 15 ohms instead of 1M.
>> > > > > >>
>> > > > > >> Ken
>> > > > > >>
>> > > > > >> >Will do.Thanks guys!
>> > > > > >> >I'll report back when i get this working.
>> > > > > >> >
>> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
>> > > > > >> <richmolindarius@> wrote:
>> > > > > >> >>
>> > > > > >> >> Use a well lit magnified lamp. Especially for that board.
Hard to find
>> > > > > >> >> small trace breaks and bad solder joints.
>> > > > > >> >>
>> > > > > >> >>
>> > > > > >> >> [Non-text portions of this message have been removed]
>> > > > > >> >>
>> > > > > >> >
>> > > > > >> >
>> > > > > >> >
>> > > > > >> >
>> > > > > >> >------------------------------------
>> > > > > >> >
>> > > > > >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> > > > > >> >Yahoo! Groups Links
>> > > > > >> >
>> > > > > >> >
>> > > > > >> >
>> > > > > >> >
>> > > > > >>
_______________________________________________________________________
>> > > > > >> Ken Stone sasami@ otherunicorn@
>> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> > > > > >> Australian Miniature Horses & Ponies
<http://www.blaze.net.au/~sasami/>
>> > > > > >>
>> > > > > >
>> > > > > >
>> > > > > >
>> > > > > >
>> > > > > >------------------------------------
>> > > > > >
>> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> > > > > >Yahoo! Groups Links
>> > > > > >
>> > > > > >
>> > > > > >
>> > > > > >
>> > > > >
_______________________________________________________________________
>> > > > > Ken Stone sasami@ otherunicorn@
>> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> > > > > Australian Miniature Horses & Ponies
<http://www.blaze.net.au/~sasami/>
>> > > > >
>> > > >
>> > >
>> >
>>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-22 by Sean

Hopefully this works? btw, I also had to use two larger 2.2M resistors in the build. One is pulled in the pic (for troubleshooting)

Thanks -Sean

http://groups.yahoo.com/group/cgs_synth/photos/album/1219515935/pic/list?mode=tn&order=ordinal&start=1&dir=asc
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Take some high res photos - IN FOCUS - of both sides so we can look at it.
> Ken
> >Yup, only connected to 1n cap and not using pad T. No shorting when chip
> is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
> checked solder joints and traces many times over. I can't help but think
> it's something else.. maybe a weird transistor or cap or mislabel resistor
> here? btw, same behavior on both LM3900s... extreme heat. Ouch.
> >
> >--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@> wrote:
> >>
> >> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
> There should be no current flow through it. Find out what pin 9 of the
> socket is short circuited to.
> >>
> >> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >> >
> >> > Been testing my voltages (with blown LM3900s removed) btw, pin 9 is
> getting burns on IC socket.
> >> >
> >> > 1) +7.50
> >> > 2) 0
> >> > 3) -7.41
> >> > 4) -14.01
> >> > 5) +3.59
> >> > 6) -0.06
> >> > 7) -14.87
> >> > 8) -0.01
> >> > 9) 0
> >> > 10) -0.10
> >> > 11) -0.06
> >> > 12) +8.06
> >> > 13) -3.34 (stepped), +5.82 (smooth)
> >> > 14) +14.86
> >> >
> >> > Strange voltages I'm getting.
> >> > -Sean
> >> >
> >> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> > >
> >> > > Sorry, that came out as a big garbled mess.
> >> > >
> >> > >
> >> > > 1) +13.54
> >> > > 2) 0
> >> > > 3) -9.23
> >> > > 4) -14.35
> >> > > 5) +11.13
> >> > > 6) -0.113
> >> > > 7) -15
> >> > > 8) -.010
> >> > > 9) 0
> >> > > 10) -.112
> >> > > 11) -.115
> >> > > 12) +13
> >> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
> >> > > 14) +15
> >> > >
> >> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> > > >
> >> > > > So all the voltages read the same on both chips except for pin 13
> which i make a note of :
> >> > > >
> >> > > > 1) +13.54 14) +15
> >> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
> >> > > > 3) -9.23 12) +13
> >> > > > 4) -14.35 11) -.115
> >> > > > 5) +11.13 10) -.112
> >> > > > 6) -0.113 9) 0
> >> > > > 7) -15 8)-.010
> >> > > >
> >> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> > > > >
> >> > > > > Seriously, chip frying is indication of serious power routing issues.
> >> > > > >
> >> > > > > With the chips OUT, read the voltages on each pin of the socket,
> then list
> >> > > > > them here.
> >> > > > >
> >> > > > > Ken
> >> > > > >
> >> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
> >> > > > > >I've triple checked component values at this point,replaced
> >> > > > > trannies,ic's,gone over continuity testing and visually inspected
> the board
> >> > > > > under a magnifying lens with no luck.
> >> > > > > >
> >> > > > > >There has to be a short or something that i am just not seeing
> because i'm
> >> > > > > getting inconsistent results when i plug it in every time i make
> a change.I
> >> > > > > fried another lm3900 in the smooth section only this time it took
> a few
> >> > > > > minutes.I've been able to get a slewed/smoothed signal to pass but no
> >> > > > > control over the hold or rate, i've gotten a steady tone from
> plugging the
> >> > > > > cycle into the in of the smooth section but again no control to
> change the
> >> > > > > pitch and now i'm back to were i started with no effect and a strong
> >> > > > > negative voltage on the outputs ?
> >> > > > > >
> >> > > > > >I'm gonna take a little break but at this point i'm seriously
> considering a
> >> > > > > do over.
> >> > > > > >
> >> > > > > >Thanks again guys i really appreciate you taking the time to
> offer your
> >> > > > > time and experience !
> >> > > > > >
> >> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> > > > > >>
> >> > > > > >> Been thinkng about this - The problem may also be caused by
> putting a
> >> > > > > >> voltage on the input pins, which are designed for current, not
> voltage.
> >> > > > > >> Check nothing is shorted to them. Check your resistor values.
> Maye sure you
> >> > > > > >> haven't installed 15 ohms instead of 1M.
> >> > > > > >>
> >> > > > > >> Ken
> >> > > > > >>
> >> > > > > >> >Will do.Thanks guys!
> >> > > > > >> >I'll report back when i get this working.
> >> > > > > >> >
> >> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> >> > > > > >> <richmolindarius@> wrote:
> >> > > > > >> >>
> >> > > > > >> >> Use a well lit magnified lamp. Especially for that board.
> Hard to find
> >> > > > > >> >> small trace breaks and bad solder joints.
> >> > > > > >> >>
> >> > > > > >> >>
> >> > > > > >> >> [Non-text portions of this message have been removed]
> >> > > > > >> >>
> >> > > > > >> >
> >> > > > > >> >
> >> > > > > >> >
> >> > > > > >> >
> >> > > > > >> >------------------------------------
> >> > > > > >> >
> >> > > > > >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> > > > > >> >Yahoo! Groups Links
> >> > > > > >> >
> >> > > > > >> >
> >> > > > > >> >
> >> > > > > >> >
> >> > > > > >>
> _______________________________________________________________________
> >> > > > > >> Ken Stone sasami@ otherunicorn@
> >> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> > > > > >> Australian Miniature Horses & Ponies
> <http://www.blaze.net.au/~sasami/>
> >> > > > > >>
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > >------------------------------------
> >> > > > > >
> >> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> > > > > >Yahoo! Groups Links
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > >
> _______________________________________________________________________
> >> > > > > Ken Stone sasami@ otherunicorn@
> >> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> > > > > Australian Miniature Horses & Ponies
> <http://www.blaze.net.au/~sasami/>
> >> > > > >
> >> > > >
> >> > >
> >> >
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-22 by Sean

Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@...> wrote:
>
> Hopefully this works? btw, I also had to use two larger 2.2M resistors in the build. One is pulled in the pic (for troubleshooting)
>
> Thanks -Sean
>
> http://groups.yahoo.com/group/cgs_synth/photos/album/1219515935/pic/list?mode=tn&order=ordinal&start=1&dir=asc
>
> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >
> > Take some high res photos - IN FOCUS - of both sides so we can look at it.
> > Ken
> > >Yup, only connected to 1n cap and not using pad T. No shorting when chip
> > is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
> > checked solder joints and traces many times over. I can't help but think
> > it's something else.. maybe a weird transistor or cap or mislabel resistor
> > here? btw, same behavior on both LM3900s... extreme heat. Ouch.
> > >
> > >--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@> wrote:
> > >>
> > >> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
> > There should be no current flow through it. Find out what pin 9 of the
> > socket is short circuited to.
> > >>
> > >> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> > >> >
> > >> > Been testing my voltages (with blown LM3900s removed) btw, pin 9 is
> > getting burns on IC socket.
> > >> >
> > >> > 1) +7.50
> > >> > 2) 0
> > >> > 3) -7.41
> > >> > 4) -14.01
> > >> > 5) +3.59
> > >> > 6) -0.06
> > >> > 7) -14.87
> > >> > 8) -0.01
> > >> > 9) 0
> > >> > 10) -0.10
> > >> > 11) -0.06
> > >> > 12) +8.06
> > >> > 13) -3.34 (stepped), +5.82 (smooth)
> > >> > 14) +14.86
> > >> >
> > >> > Strange voltages I'm getting.
> > >> > -Sean
> > >> >
> > >> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> > >> > >
> > >> > > Sorry, that came out as a big garbled mess.
> > >> > >
> > >> > >
> > >> > > 1) +13.54
> > >> > > 2) 0
> > >> > > 3) -9.23
> > >> > > 4) -14.35
> > >> > > 5) +11.13
> > >> > > 6) -0.113
> > >> > > 7) -15
> > >> > > 8) -.010
> > >> > > 9) 0
> > >> > > 10) -.112
> > >> > > 11) -.115
> > >> > > 12) +13
> > >> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
> > >> > > 14) +15
> > >> > >
> > >> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> > >> > > >
> > >> > > > So all the voltages read the same on both chips except for pin 13
> > which i make a note of :
> > >> > > >
> > >> > > > 1) +13.54 14) +15
> > >> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
> > >> > > > 3) -9.23 12) +13
> > >> > > > 4) -14.35 11) -.115
> > >> > > > 5) +11.13 10) -.112
> > >> > > > 6) -0.113 9) 0
> > >> > > > 7) -15 8)-.010
> > >> > > >
> > >> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > >> > > > >
> > >> > > > > Seriously, chip frying is indication of serious power routing issues.
> > >> > > > >
> > >> > > > > With the chips OUT, read the voltages on each pin of the socket,
> > then list
> > >> > > > > them here.
> > >> > > > >
> > >> > > > > Ken
> > >> > > > >
> > >> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
> > >> > > > > >I've triple checked component values at this point,replaced
> > >> > > > > trannies,ic's,gone over continuity testing and visually inspected
> > the board
> > >> > > > > under a magnifying lens with no luck.
> > >> > > > > >
> > >> > > > > >There has to be a short or something that i am just not seeing
> > because i'm
> > >> > > > > getting inconsistent results when i plug it in every time i make
> > a change.I
> > >> > > > > fried another lm3900 in the smooth section only this time it took
> > a few
> > >> > > > > minutes.I've been able to get a slewed/smoothed signal to pass but no
> > >> > > > > control over the hold or rate, i've gotten a steady tone from
> > plugging the
> > >> > > > > cycle into the in of the smooth section but again no control to
> > change the
> > >> > > > > pitch and now i'm back to were i started with no effect and a strong
> > >> > > > > negative voltage on the outputs ?
> > >> > > > > >
> > >> > > > > >I'm gonna take a little break but at this point i'm seriously
> > considering a
> > >> > > > > do over.
> > >> > > > > >
> > >> > > > > >Thanks again guys i really appreciate you taking the time to
> > offer your
> > >> > > > > time and experience !
> > >> > > > > >
> > >> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > >> > > > > >>
> > >> > > > > >> Been thinkng about this - The problem may also be caused by
> > putting a
> > >> > > > > >> voltage on the input pins, which are designed for current, not
> > voltage.
> > >> > > > > >> Check nothing is shorted to them. Check your resistor values.
> > Maye sure you
> > >> > > > > >> haven't installed 15 ohms instead of 1M.
> > >> > > > > >>
> > >> > > > > >> Ken
> > >> > > > > >>
> > >> > > > > >> >Will do.Thanks guys!
> > >> > > > > >> >I'll report back when i get this working.
> > >> > > > > >> >
> > >> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> > >> > > > > >> <richmolindarius@> wrote:
> > >> > > > > >> >>
> > >> > > > > >> >> Use a well lit magnified lamp. Especially for that board.
> > Hard to find
> > >> > > > > >> >> small trace breaks and bad solder joints.
> > >> > > > > >> >>
> > >> > > > > >> >>
> > >> > > > > >> >> [Non-text portions of this message have been removed]
> > >> > > > > >> >>
> > >> > > > > >> >
> > >> > > > > >> >
> > >> > > > > >> >
> > >> > > > > >> >
> > >> > > > > >> >------------------------------------
> > >> > > > > >> >
> > >> > > > > >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > >> > > > > >> >Yahoo! Groups Links
> > >> > > > > >> >
> > >> > > > > >> >
> > >> > > > > >> >
> > >> > > > > >> >
> > >> > > > > >>
> > _______________________________________________________________________
> > >> > > > > >> Ken Stone sasami@ otherunicorn@
> > >> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > >> > > > > >> Australian Miniature Horses & Ponies
> > <http://www.blaze.net.au/~sasami/>
> > >> > > > > >>
> > >> > > > > >
> > >> > > > > >
> > >> > > > > >
> > >> > > > > >
> > >> > > > > >------------------------------------
> > >> > > > > >
> > >> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > >> > > > > >Yahoo! Groups Links
> > >> > > > > >
> > >> > > > > >
> > >> > > > > >
> > >> > > > > >
> > >> > > > >
> > _______________________________________________________________________
> > >> > > > > Ken Stone sasami@ otherunicorn@
> > >> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> > >> > > > > Australian Miniature Horses & Ponies
> > <http://www.blaze.net.au/~sasami/>
> > >> > > > >
> > >> > > >
> > >> > >
> > >> >
> > >>
> > >
> > >
> > >
> > >
> > >------------------------------------
> > >
> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> > >Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > _______________________________________________________________________
> > Ken Stone sasami@ otherunicorn@
> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-23 by cg_synth

Looked it all over. Compared it with mine. Can't see anything obviously amiss.
My thoughts:
1) check that the PN4250 are in the correct way. I can see you have them
according to the overlay, but perhaps the transistors are reversed int he
package. (all the same, I don't see how this would have any effect on your
problem.
2) I guess it is possible that it is the LM3900 chips themselves that are no
good. If someone has relabeled CA3401 and sold them as LM3900, you would
expect trouble, as the CA3401 is only good to 15V, unlike the LM3900 that
can go up to 30V. They aren't NTE or something like that, are they?
3)I can't read the 1n caps, so I can't say they are the right part.
(0.001uF, 1n, 1000pF).

Ken
Show quoted textHide quoted text
>Maybe, slightly better pic of back...
>https://sphotos-a.xx.fbcdn.net/hphotos-ash4/317422_10151631973766807_174487
4777_n.jpg
>
>
>--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@...> wrote:
>>
>> Hopefully this works? btw, I also had to use two larger 2.2M resistors
in the build. One is pulled in the pic (for troubleshooting)
>>
>> Thanks -Sean
>>
>>
http://groups.yahoo.com/group/cgs_synth/photos/album/1219515935/pic/list?mod
e=tn&order=ordinal&start=1&dir=asc
>>
>> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> >
>> > Take some high res photos - IN FOCUS - of both sides so we can look at it.
>> > Ken
>> > >Yup, only connected to 1n cap and not using pad T. No shorting when chip
>> > is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
>> > checked solder joints and traces many times over. I can't help but think
>> > it's something else.. maybe a weird transistor or cap or mislabel resistor
>> > here? btw, same behavior on both LM3900s... extreme heat. Ouch.
>> > >
>> > >--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@> wrote:
>> > >>
>> > >> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
>> > There should be no current flow through it. Find out what pin 9 of the
>> > socket is short circuited to.
>> > >>
>> > >> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
>> > >> >
>> > >> > Been testing my voltages (with blown LM3900s removed) btw, pin 9 is
>> > getting burns on IC socket.
>> > >> >
>> > >> > 1) +7.50
>> > >> > 2) 0
>> > >> > 3) -7.41
>> > >> > 4) -14.01
>> > >> > 5) +3.59
>> > >> > 6) -0.06
>> > >> > 7) -14.87
>> > >> > 8) -0.01
>> > >> > 9) 0
>> > >> > 10) -0.10
>> > >> > 11) -0.06
>> > >> > 12) +8.06
>> > >> > 13) -3.34 (stepped), +5.82 (smooth)
>> > >> > 14) +14.86
>> > >> >
>> > >> > Strange voltages I'm getting.
>> > >> > -Sean
>> > >> >
>> > >> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
>> > >> > >
>> > >> > > Sorry, that came out as a big garbled mess.
>> > >> > >
>> > >> > >
>> > >> > > 1) +13.54
>> > >> > > 2) 0
>> > >> > > 3) -9.23
>> > >> > > 4) -14.35
>> > >> > > 5) +11.13
>> > >> > > 6) -0.113
>> > >> > > 7) -15
>> > >> > > 8) -.010
>> > >> > > 9) 0
>> > >> > > 10) -.112
>> > >> > > 11) -.115
>> > >> > > 12) +13
>> > >> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
>> > >> > > 14) +15
>> > >> > >
>> > >> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
>> > >> > > >
>> > >> > > > So all the voltages read the same on both chips except for pin 13
>> > which i make a note of :
>> > >> > > >
>> > >> > > > 1) +13.54 14) +15
>> > >> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
>> > >> > > > 3) -9.23 12) +13
>> > >> > > > 4) -14.35 11) -.115
>> > >> > > > 5) +11.13 10) -.112
>> > >> > > > 6) -0.113 9) 0
>> > >> > > > 7) -15 8)-.010
>> > >> > > >
>> > >> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> > >> > > > >
>> > >> > > > > Seriously, chip frying is indication of serious power
routing issues.
>> > >> > > > >
>> > >> > > > > With the chips OUT, read the voltages on each pin of the socket,
>> > then list
>> > >> > > > > them here.
>> > >> > > > >
>> > >> > > > > Ken
>> > >> > > > >
>> > >> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
>> > >> > > > > >I've triple checked component values at this point,replaced
>> > >> > > > > trannies,ic's,gone over continuity testing and visually
inspected
>> > the board
>> > >> > > > > under a magnifying lens with no luck.
>> > >> > > > > >
>> > >> > > > > >There has to be a short or something that i am just not seeing
>> > because i'm
>> > >> > > > > getting inconsistent results when i plug it in every time i make
>> > a change.I
>> > >> > > > > fried another lm3900 in the smooth section only this time it
took
>> > a few
>> > >> > > > > minutes.I've been able to get a slewed/smoothed signal to
pass but no
>> > >> > > > > control over the hold or rate, i've gotten a steady tone from
>> > plugging the
>> > >> > > > > cycle into the in of the smooth section but again no control to
>> > change the
>> > >> > > > > pitch and now i'm back to were i started with no effect and
a strong
>> > >> > > > > negative voltage on the outputs ?
>> > >> > > > > >
>> > >> > > > > >I'm gonna take a little break but at this point i'm seriously
>> > considering a
>> > >> > > > > do over.
>> > >> > > > > >
>> > >> > > > > >Thanks again guys i really appreciate you taking the time to
>> > offer your
>> > >> > > > > time and experience !
>> > >> > > > > >
>> > >> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> > >> > > > > >>
>> > >> > > > > >> Been thinkng about this - The problem may also be caused by
>> > putting a
>> > >> > > > > >> voltage on the input pins, which are designed for
current, not
>> > voltage.
>> > >> > > > > >> Check nothing is shorted to them. Check your resistor values.
>> > Maye sure you
>> > >> > > > > >> haven't installed 15 ohms instead of 1M.
>> > >> > > > > >>
>> > >> > > > > >> Ken
>> > >> > > > > >>
>> > >> > > > > >> >Will do.Thanks guys!
>> > >> > > > > >> >I'll report back when i get this working.
>> > >> > > > > >> >
>> > >> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
>> > >> > > > > >> <richmolindarius@> wrote:
>> > >> > > > > >> >>
>> > >> > > > > >> >> Use a well lit magnified lamp. Especially for that board.
>> > Hard to find
>> > >> > > > > >> >> small trace breaks and bad solder joints.
>> > >> > > > > >> >>
>> > >> > > > > >> >>
>> > >> > > > > >> >> [Non-text portions of this message have been removed]
>> > >> > > > > >> >>
>> > >> > > > > >> >
>> > >> > > > > >> >
>> > >> > > > > >> >
>> > >> > > > > >> >
>> > >> > > > > >> >------------------------------------
>> > >> > > > > >> >
>> > >> > > > > >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> > >> > > > > >> >Yahoo! Groups Links
>> > >> > > > > >> >
>> > >> > > > > >> >
>> > >> > > > > >> >
>> > >> > > > > >> >
>> > >> > > > > >>
>> > _______________________________________________________________________
>> > >> > > > > >> Ken Stone sasami@ otherunicorn@
>> > >> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> > >> > > > > >> Australian Miniature Horses & Ponies
>> > <http://www.blaze.net.au/~sasami/>
>> > >> > > > > >>
>> > >> > > > > >
>> > >> > > > > >
>> > >> > > > > >
>> > >> > > > > >
>> > >> > > > > >------------------------------------
>> > >> > > > > >
>> > >> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> > >> > > > > >Yahoo! Groups Links
>> > >> > > > > >
>> > >> > > > > >
>> > >> > > > > >
>> > >> > > > > >
>> > >> > > > >
>> > _______________________________________________________________________
>> > >> > > > > Ken Stone sasami@ otherunicorn@
>> > >> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> > >> > > > > Australian Miniature Horses & Ponies
>> > <http://www.blaze.net.au/~sasami/>
>> > >> > > > >
>> > >> > > >
>> > >> > >
>> > >> >
>> > >>
>> > >
>> > >
>> > >
>> > >
>> > >------------------------------------
>> > >
>> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> > >Yahoo! Groups Links
>> > >
>> > >
>> > >
>> > >
>> > _______________________________________________________________________
>> > Ken Stone sasami@ otherunicorn@
>> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> >
>>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-23 by Sean

One thing of interest, I bought the LM3900s and they say LM3900 on the chips but the package they came in said LM339. But I just figured they used containers they had on hand. I'll pick up some other LM3900s and give it a shot and I'll do a little research on PN4250s I used.

Thanks, Sean
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Looked it all over. Compared it with mine. Can't see anything obviously amiss.
> My thoughts:
> 1) check that the PN4250 are in the correct way. I can see you have them
> according to the overlay, but perhaps the transistors are reversed int he
> package. (all the same, I don't see how this would have any effect on your
> problem.
> 2) I guess it is possible that it is the LM3900 chips themselves that are no
> good. If someone has relabeled CA3401 and sold them as LM3900, you would
> expect trouble, as the CA3401 is only good to 15V, unlike the LM3900 that
> can go up to 30V. They aren't NTE or something like that, are they?
> 3)I can't read the 1n caps, so I can't say they are the right part.
> (0.001uF, 1n, 1000pF).
>
> Ken
>
> >Maybe, slightly better pic of back...
> >https://sphotos-a.xx.fbcdn.net/hphotos-ash4/317422_10151631973766807_174487
> 4777_n.jpg
> >
> >
> >--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >>
> >> Hopefully this works? btw, I also had to use two larger 2.2M resistors
> in the build. One is pulled in the pic (for troubleshooting)
> >>
> >> Thanks -Sean
> >>
> >>
> http://groups.yahoo.com/group/cgs_synth/photos/album/1219515935/pic/list?mod
> e=tn&order=ordinal&start=1&dir=asc
> >>
> >> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> >
> >> > Take some high res photos - IN FOCUS - of both sides so we can look at it.
> >> > Ken
> >> > >Yup, only connected to 1n cap and not using pad T. No shorting when chip
> >> > is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
> >> > checked solder joints and traces many times over. I can't help but think
> >> > it's something else.. maybe a weird transistor or cap or mislabel resistor
> >> > here? btw, same behavior on both LM3900s... extreme heat. Ouch.
> >> > >
> >> > >--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@> wrote:
> >> > >>
> >> > >> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
> >> > There should be no current flow through it. Find out what pin 9 of the
> >> > socket is short circuited to.
> >> > >>
> >> > >> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >> > >> >
> >> > >> > Been testing my voltages (with blown LM3900s removed) btw, pin 9 is
> >> > getting burns on IC socket.
> >> > >> >
> >> > >> > 1) +7.50
> >> > >> > 2) 0
> >> > >> > 3) -7.41
> >> > >> > 4) -14.01
> >> > >> > 5) +3.59
> >> > >> > 6) -0.06
> >> > >> > 7) -14.87
> >> > >> > 8) -0.01
> >> > >> > 9) 0
> >> > >> > 10) -0.10
> >> > >> > 11) -0.06
> >> > >> > 12) +8.06
> >> > >> > 13) -3.34 (stepped), +5.82 (smooth)
> >> > >> > 14) +14.86
> >> > >> >
> >> > >> > Strange voltages I'm getting.
> >> > >> > -Sean
> >> > >> >
> >> > >> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> > >> > >
> >> > >> > > Sorry, that came out as a big garbled mess.
> >> > >> > >
> >> > >> > >
> >> > >> > > 1) +13.54
> >> > >> > > 2) 0
> >> > >> > > 3) -9.23
> >> > >> > > 4) -14.35
> >> > >> > > 5) +11.13
> >> > >> > > 6) -0.113
> >> > >> > > 7) -15
> >> > >> > > 8) -.010
> >> > >> > > 9) 0
> >> > >> > > 10) -.112
> >> > >> > > 11) -.115
> >> > >> > > 12) +13
> >> > >> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
> >> > >> > > 14) +15
> >> > >> > >
> >> > >> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> > >> > > >
> >> > >> > > > So all the voltages read the same on both chips except for pin 13
> >> > which i make a note of :
> >> > >> > > >
> >> > >> > > > 1) +13.54 14) +15
> >> > >> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
> >> > >> > > > 3) -9.23 12) +13
> >> > >> > > > 4) -14.35 11) -.115
> >> > >> > > > 5) +11.13 10) -.112
> >> > >> > > > 6) -0.113 9) 0
> >> > >> > > > 7) -15 8)-.010
> >> > >> > > >
> >> > >> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> > >> > > > >
> >> > >> > > > > Seriously, chip frying is indication of serious power
> routing issues.
> >> > >> > > > >
> >> > >> > > > > With the chips OUT, read the voltages on each pin of the socket,
> >> > then list
> >> > >> > > > > them here.
> >> > >> > > > >
> >> > >> > > > > Ken
> >> > >> > > > >
> >> > >> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
> >> > >> > > > > >I've triple checked component values at this point,replaced
> >> > >> > > > > trannies,ic's,gone over continuity testing and visually
> inspected
> >> > the board
> >> > >> > > > > under a magnifying lens with no luck.
> >> > >> > > > > >
> >> > >> > > > > >There has to be a short or something that i am just not seeing
> >> > because i'm
> >> > >> > > > > getting inconsistent results when i plug it in every time i make
> >> > a change.I
> >> > >> > > > > fried another lm3900 in the smooth section only this time it
> took
> >> > a few
> >> > >> > > > > minutes.I've been able to get a slewed/smoothed signal to
> pass but no
> >> > >> > > > > control over the hold or rate, i've gotten a steady tone from
> >> > plugging the
> >> > >> > > > > cycle into the in of the smooth section but again no control to
> >> > change the
> >> > >> > > > > pitch and now i'm back to were i started with no effect and
> a strong
> >> > >> > > > > negative voltage on the outputs ?
> >> > >> > > > > >
> >> > >> > > > > >I'm gonna take a little break but at this point i'm seriously
> >> > considering a
> >> > >> > > > > do over.
> >> > >> > > > > >
> >> > >> > > > > >Thanks again guys i really appreciate you taking the time to
> >> > offer your
> >> > >> > > > > time and experience !
> >> > >> > > > > >
> >> > >> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> > >> > > > > >>
> >> > >> > > > > >> Been thinkng about this - The problem may also be caused by
> >> > putting a
> >> > >> > > > > >> voltage on the input pins, which are designed for
> current, not
> >> > voltage.
> >> > >> > > > > >> Check nothing is shorted to them. Check your resistor values.
> >> > Maye sure you
> >> > >> > > > > >> haven't installed 15 ohms instead of 1M.
> >> > >> > > > > >>
> >> > >> > > > > >> Ken
> >> > >> > > > > >>
> >> > >> > > > > >> >Will do.Thanks guys!
> >> > >> > > > > >> >I'll report back when i get this working.
> >> > >> > > > > >> >
> >> > >> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> >> > >> > > > > >> <richmolindarius@> wrote:
> >> > >> > > > > >> >>
> >> > >> > > > > >> >> Use a well lit magnified lamp. Especially for that board.
> >> > Hard to find
> >> > >> > > > > >> >> small trace breaks and bad solder joints.
> >> > >> > > > > >> >>
> >> > >> > > > > >> >>
> >> > >> > > > > >> >> [Non-text portions of this message have been removed]
> >> > >> > > > > >> >>
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >> >------------------------------------
> >> > >> > > > > >> >
> >> > >> > > > > >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> > >> > > > > >> >Yahoo! Groups Links
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >>
> >> > _______________________________________________________________________
> >> > >> > > > > >> Ken Stone sasami@ otherunicorn@
> >> > >> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> > >> > > > > >> Australian Miniature Horses & Ponies
> >> > <http://www.blaze.net.au/~sasami/>
> >> > >> > > > > >>
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >------------------------------------
> >> > >> > > > > >
> >> > >> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> > >> > > > > >Yahoo! Groups Links
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > >
> >> > _______________________________________________________________________
> >> > >> > > > > Ken Stone sasami@ otherunicorn@
> >> > >> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> > >> > > > > Australian Miniature Horses & Ponies
> >> > <http://www.blaze.net.au/~sasami/>
> >> > >> > > > >
> >> > >> > > >
> >> > >> > >
> >> > >> >
> >> > >>
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >------------------------------------
> >> > >
> >> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> > >Yahoo! Groups Links
> >> > >
> >> > >
> >> > >
> >> > >
> >> > _______________________________________________________________________
> >> > Ken Stone sasami@ otherunicorn@
> >> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> >
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-23 by cg_synth

What manufacturer were the chips?

Ken

>One thing of interest, I bought the LM3900s and they say LM3900 on the
chips but the package they came in said LM339. But I just figured they used
containers they had on hand. I'll pick up some other LM3900s and give it a
shot and I'll do a little research on PN4250s I used.
>
>Thanks, Sean
>
>--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>>
>> Looked it all over. Compared it with mine. Can't see anything obviously
amiss.
>> My thoughts:
>> 1) check that the PN4250 are in the correct way. I can see you have them
>> according to the overlay, but perhaps the transistors are reversed int he
>> package. (all the same, I don't see how this would have any effect on your
>> problem.
>> 2) I guess it is possible that it is the LM3900 chips themselves that are no
>> good. If someone has relabeled CA3401 and sold them as LM3900, you would
>> expect trouble, as the CA3401 is only good to 15V, unlike the LM3900 that
>> can go up to 30V. They aren't NTE or something like that, are they?
>> 3)I can't read the 1n caps, so I can't say they are the right part.
>> (0.001uF, 1n, 1000pF).
>>
>> Ken
>>
>> >Maybe, slightly better pic of back...
>> >https://sphotos-a.xx.fbcdn.net/hphotos-ash4/317422_10151631973766807_174487
>> 4777_n.jpg
>> >
>> >
>> >--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
>> >>
>> >> Hopefully this works? btw, I also had to use two larger 2.2M resistors
>> in the build. One is pulled in the pic (for troubleshooting)
>> >>
>> >> Thanks -Sean
>> >>
>> >>
>> http://groups.yahoo.com/group/cgs_synth/photos/album/1219515935/pic/list?mod
>> e=tn&order=ordinal&start=1&dir=asc
>> >>
>> >> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> >> >
>> >> > Take some high res photos - IN FOCUS - of both sides so we can look
at it.
>> >> > Ken
>> >> > >Yup, only connected to 1n cap and not using pad T. No shorting
when chip
>> >> > is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
>> >> > checked solder joints and traces many times over. I can't help but
think
>> >> > it's something else.. maybe a weird transistor or cap or mislabel
resistor
>> >> > here? btw, same behavior on both LM3900s... extreme heat. Ouch.
>> >> > >
>> >> > >--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@> wrote:
>> >> > >>
>> >> > >> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
>> >> > There should be no current flow through it. Find out what pin 9 of the
>> >> > socket is short circuited to.
>> >> > >>
>> >> > >> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
>> >> > >> >
>> >> > >> > Been testing my voltages (with blown LM3900s removed) btw, pin
9 is
>> >> > getting burns on IC socket.
>> >> > >> >
>> >> > >> > 1) +7.50
>> >> > >> > 2) 0
>> >> > >> > 3) -7.41
>> >> > >> > 4) -14.01
>> >> > >> > 5) +3.59
>> >> > >> > 6) -0.06
>> >> > >> > 7) -14.87
>> >> > >> > 8) -0.01
>> >> > >> > 9) 0
>> >> > >> > 10) -0.10
>> >> > >> > 11) -0.06
>> >> > >> > 12) +8.06
>> >> > >> > 13) -3.34 (stepped), +5.82 (smooth)
>> >> > >> > 14) +14.86
>> >> > >> >
>> >> > >> > Strange voltages I'm getting.
>> >> > >> > -Sean
>> >> > >> >
>> >> > >> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
>> >> > >> > >
>> >> > >> > > Sorry, that came out as a big garbled mess.
>> >> > >> > >
>> >> > >> > >
>> >> > >> > > 1) +13.54
>> >> > >> > > 2) 0
>> >> > >> > > 3) -9.23
>> >> > >> > > 4) -14.35
>> >> > >> > > 5) +11.13
>> >> > >> > > 6) -0.113
>> >> > >> > > 7) -15
>> >> > >> > > 8) -.010
>> >> > >> > > 9) 0
>> >> > >> > > 10) -.112
>> >> > >> > > 11) -.115
>> >> > >> > > 12) +13
>> >> > >> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
>> >> > >> > > 14) +15
>> >> > >> > >
>> >> > >> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
>> >> > >> > > >
>> >> > >> > > > So all the voltages read the same on both chips except for
pin 13
>> >> > which i make a note of :
>> >> > >> > > >
>> >> > >> > > > 1) +13.54 14) +15
>> >> > >> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
>> >> > >> > > > 3) -9.23 12) +13
>> >> > >> > > > 4) -14.35 11) -.115
>> >> > >> > > > 5) +11.13 10) -.112
>> >> > >> > > > 6) -0.113 9) 0
>> >> > >> > > > 7) -15 8)-.010
>> >> > >> > > >
>> >> > >> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> >> > >> > > > >
>> >> > >> > > > > Seriously, chip frying is indication of serious power
>> routing issues.
>> >> > >> > > > >
>> >> > >> > > > > With the chips OUT, read the voltages on each pin of the
socket,
>> >> > then list
>> >> > >> > > > > them here.
>> >> > >> > > > >
>> >> > >> > > > > Ken
>> >> > >> > > > >
>> >> > >> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
>> >> > >> > > > > >I've triple checked component values at this point,replaced
>> >> > >> > > > > trannies,ic's,gone over continuity testing and visually
>> inspected
>> >> > the board
>> >> > >> > > > > under a magnifying lens with no luck.
>> >> > >> > > > > >
>> >> > >> > > > > >There has to be a short or something that i am just not
seeing
>> >> > because i'm
>> >> > >> > > > > getting inconsistent results when i plug it in every time
i make
>> >> > a change.I
>> >> > >> > > > > fried another lm3900 in the smooth section only this time it
>> took
>> >> > a few
>> >> > >> > > > > minutes.I've been able to get a slewed/smoothed signal to
>> pass but no
>> >> > >> > > > > control over the hold or rate, i've gotten a steady tone from
>> >> > plugging the
>> >> > >> > > > > cycle into the in of the smooth section but again no
control to
>> >> > change the
>> >> > >> > > > > pitch and now i'm back to were i started with no effect and
>> a strong
>> >> > >> > > > > negative voltage on the outputs ?
>> >> > >> > > > > >
>> >> > >> > > > > >I'm gonna take a little break but at this point i'm
seriously
>> >> > considering a
>> >> > >> > > > > do over.
>> >> > >> > > > > >
>> >> > >> > > > > >Thanks again guys i really appreciate you taking the time to
>> >> > offer your
>> >> > >> > > > > time and experience !
>> >> > >> > > > > >
>> >> > >> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> >> > >> > > > > >>
>> >> > >> > > > > >> Been thinkng about this - The problem may also be
caused by
>> >> > putting a
>> >> > >> > > > > >> voltage on the input pins, which are designed for
>> current, not
>> >> > voltage.
>> >> > >> > > > > >> Check nothing is shorted to them. Check your resistor
values.
>> >> > Maye sure you
>> >> > >> > > > > >> haven't installed 15 ohms instead of 1M.
>> >> > >> > > > > >>
>> >> > >> > > > > >> Ken
>> >> > >> > > > > >>
>> >> > >> > > > > >> >Will do.Thanks guys!
>> >> > >> > > > > >> >I'll report back when i get this working.
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
>> >> > >> > > > > >> <richmolindarius@> wrote:
>> >> > >> > > > > >> >>
>> >> > >> > > > > >> >> Use a well lit magnified lamp. Especially for that
board.
>> >> > Hard to find
>> >> > >> > > > > >> >> small trace breaks and bad solder joints.
>> >> > >> > > > > >> >>
>> >> > >> > > > > >> >>
>> >> > >> > > > > >> >> [Non-text portions of this message have been removed]
>> >> > >> > > > > >> >>
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >------------------------------------
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >The CGS Modular Synth home page:
http://www.cgs.synth.net/
>> >> > >> > > > > >> >Yahoo! Groups Links
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >>
>> >> > _______________________________________________________________________
>> >> > >> > > > > >> Ken Stone sasami@ otherunicorn@
>> >> > >> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> >> > >> > > > > >> Australian Miniature Horses & Ponies
>> >> > <http://www.blaze.net.au/~sasami/>
>> >> > >> > > > > >>
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > > >------------------------------------
>> >> > >> > > > > >
>> >> > >> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> >> > >> > > > > >Yahoo! Groups Links
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > >
>> >> > _______________________________________________________________________
>> >> > >> > > > > Ken Stone sasami@ otherunicorn@
>> >> > >> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> >> > >> > > > > Australian Miniature Horses & Ponies
>> >> > <http://www.blaze.net.au/~sasami/>
>> >> > >> > > > >
>> >> > >> > > >
>> >> > >> > >
>> >> > >> >
>> >> > >>
>> >> > >
>> >> > >
>> >> > >
>> >> > >
>> >> > >------------------------------------
>> >> > >
>> >> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> >> > >Yahoo! Groups Links
>> >> > >
>> >> > >
>> >> > >
>> >> > >
>> >> > _______________________________________________________________________
>> >> > Ken Stone sasami@ otherunicorn@
>> >> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> >> >
>> >>
>> >
>> >
>> >
>> >
>> >------------------------------------
>> >
>> >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> >Yahoo! Groups Links
>> >
>> >
>> >
>> >
>> _______________________________________________________________________
>> Ken Stone sasami@... otherunicorn@...
>> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-23 by Sean

Texas Instruments.

--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> What manufacturer were the chips?
>
> Ken
>
> >One thing of interest, I bought the LM3900s and they say LM3900 on the
> chips but the package they came in said LM339. But I just figured they used
> containers they had on hand. I'll pick up some other LM3900s and give it a
> shot and I'll do a little research on PN4250s I used.
> >
> >Thanks, Sean
> >
> >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >>
> >> Looked it all over. Compared it with mine. Can't see anything obviously
> amiss.
> >> My thoughts:
> >> 1) check that the PN4250 are in the correct way. I can see you have them
> >> according to the overlay, but perhaps the transistors are reversed int he
> >> package. (all the same, I don't see how this would have any effect on your
> >> problem.
> >> 2) I guess it is possible that it is the LM3900 chips themselves that are no
> >> good. If someone has relabeled CA3401 and sold them as LM3900, you would
> >> expect trouble, as the CA3401 is only good to 15V, unlike the LM3900 that
> >> can go up to 30V. They aren't NTE or something like that, are they?
> >> 3)I can't read the 1n caps, so I can't say they are the right part.
> >> (0.001uF, 1n, 1000pF).
> >>
> >> Ken
> >>
> >> >Maybe, slightly better pic of back...
> >> >https://sphotos-a.xx.fbcdn.net/hphotos-ash4/317422_10151631973766807_174487
> >> 4777_n.jpg
> >> >
> >> >
> >> >--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >> >>
> >> >> Hopefully this works? btw, I also had to use two larger 2.2M resistors
> >> in the build. One is pulled in the pic (for troubleshooting)
> >> >>
> >> >> Thanks -Sean
> >> >>
> >> >>
> >> http://groups.yahoo.com/group/cgs_synth/photos/album/1219515935/pic/list?mod
> >> e=tn&order=ordinal&start=1&dir=asc
> >> >>
> >> >> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> >> >
> >> >> > Take some high res photos - IN FOCUS - of both sides so we can look
> at it.
> >> >> > Ken
> >> >> > >Yup, only connected to 1n cap and not using pad T. No shorting
> when chip
> >> >> > is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
> >> >> > checked solder joints and traces many times over. I can't help but
> think
> >> >> > it's something else.. maybe a weird transistor or cap or mislabel
> resistor
> >> >> > here? btw, same behavior on both LM3900s... extreme heat. Ouch.
> >> >> > >
> >> >> > >--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@> wrote:
> >> >> > >>
> >> >> > >> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
> >> >> > There should be no current flow through it. Find out what pin 9 of the
> >> >> > socket is short circuited to.
> >> >> > >>
> >> >> > >> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >> >> > >> >
> >> >> > >> > Been testing my voltages (with blown LM3900s removed) btw, pin
> 9 is
> >> >> > getting burns on IC socket.
> >> >> > >> >
> >> >> > >> > 1) +7.50
> >> >> > >> > 2) 0
> >> >> > >> > 3) -7.41
> >> >> > >> > 4) -14.01
> >> >> > >> > 5) +3.59
> >> >> > >> > 6) -0.06
> >> >> > >> > 7) -14.87
> >> >> > >> > 8) -0.01
> >> >> > >> > 9) 0
> >> >> > >> > 10) -0.10
> >> >> > >> > 11) -0.06
> >> >> > >> > 12) +8.06
> >> >> > >> > 13) -3.34 (stepped), +5.82 (smooth)
> >> >> > >> > 14) +14.86
> >> >> > >> >
> >> >> > >> > Strange voltages I'm getting.
> >> >> > >> > -Sean
> >> >> > >> >
> >> >> > >> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> >> > >> > >
> >> >> > >> > > Sorry, that came out as a big garbled mess.
> >> >> > >> > >
> >> >> > >> > >
> >> >> > >> > > 1) +13.54
> >> >> > >> > > 2) 0
> >> >> > >> > > 3) -9.23
> >> >> > >> > > 4) -14.35
> >> >> > >> > > 5) +11.13
> >> >> > >> > > 6) -0.113
> >> >> > >> > > 7) -15
> >> >> > >> > > 8) -.010
> >> >> > >> > > 9) 0
> >> >> > >> > > 10) -.112
> >> >> > >> > > 11) -.115
> >> >> > >> > > 12) +13
> >> >> > >> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
> >> >> > >> > > 14) +15
> >> >> > >> > >
> >> >> > >> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> >> > >> > > >
> >> >> > >> > > > So all the voltages read the same on both chips except for
> pin 13
> >> >> > which i make a note of :
> >> >> > >> > > >
> >> >> > >> > > > 1) +13.54 14) +15
> >> >> > >> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
> >> >> > >> > > > 3) -9.23 12) +13
> >> >> > >> > > > 4) -14.35 11) -.115
> >> >> > >> > > > 5) +11.13 10) -.112
> >> >> > >> > > > 6) -0.113 9) 0
> >> >> > >> > > > 7) -15 8)-.010
> >> >> > >> > > >
> >> >> > >> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> >> > >> > > > >
> >> >> > >> > > > > Seriously, chip frying is indication of serious power
> >> routing issues.
> >> >> > >> > > > >
> >> >> > >> > > > > With the chips OUT, read the voltages on each pin of the
> socket,
> >> >> > then list
> >> >> > >> > > > > them here.
> >> >> > >> > > > >
> >> >> > >> > > > > Ken
> >> >> > >> > > > >
> >> >> > >> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
> >> >> > >> > > > > >I've triple checked component values at this point,replaced
> >> >> > >> > > > > trannies,ic's,gone over continuity testing and visually
> >> inspected
> >> >> > the board
> >> >> > >> > > > > under a magnifying lens with no luck.
> >> >> > >> > > > > >
> >> >> > >> > > > > >There has to be a short or something that i am just not
> seeing
> >> >> > because i'm
> >> >> > >> > > > > getting inconsistent results when i plug it in every time
> i make
> >> >> > a change.I
> >> >> > >> > > > > fried another lm3900 in the smooth section only this time it
> >> took
> >> >> > a few
> >> >> > >> > > > > minutes.I've been able to get a slewed/smoothed signal to
> >> pass but no
> >> >> > >> > > > > control over the hold or rate, i've gotten a steady tone from
> >> >> > plugging the
> >> >> > >> > > > > cycle into the in of the smooth section but again no
> control to
> >> >> > change the
> >> >> > >> > > > > pitch and now i'm back to were i started with no effect and
> >> a strong
> >> >> > >> > > > > negative voltage on the outputs ?
> >> >> > >> > > > > >
> >> >> > >> > > > > >I'm gonna take a little break but at this point i'm
> seriously
> >> >> > considering a
> >> >> > >> > > > > do over.
> >> >> > >> > > > > >
> >> >> > >> > > > > >Thanks again guys i really appreciate you taking the time to
> >> >> > offer your
> >> >> > >> > > > > time and experience !
> >> >> > >> > > > > >
> >> >> > >> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> >> > >> > > > > >>
> >> >> > >> > > > > >> Been thinkng about this - The problem may also be
> caused by
> >> >> > putting a
> >> >> > >> > > > > >> voltage on the input pins, which are designed for
> >> current, not
> >> >> > voltage.
> >> >> > >> > > > > >> Check nothing is shorted to them. Check your resistor
> values.
> >> >> > Maye sure you
> >> >> > >> > > > > >> haven't installed 15 ohms instead of 1M.
> >> >> > >> > > > > >>
> >> >> > >> > > > > >> Ken
> >> >> > >> > > > > >>
> >> >> > >> > > > > >> >Will do.Thanks guys!
> >> >> > >> > > > > >> >I'll report back when i get this working.
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> >> >> > >> > > > > >> <richmolindarius@> wrote:
> >> >> > >> > > > > >> >>
> >> >> > >> > > > > >> >> Use a well lit magnified lamp. Especially for that
> board.
> >> >> > Hard to find
> >> >> > >> > > > > >> >> small trace breaks and bad solder joints.
> >> >> > >> > > > > >> >>
> >> >> > >> > > > > >> >>
> >> >> > >> > > > > >> >> [Non-text portions of this message have been removed]
> >> >> > >> > > > > >> >>
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >------------------------------------
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >The CGS Modular Synth home page:
> http://www.cgs.synth.net/
> >> >> > >> > > > > >> >Yahoo! Groups Links
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >>
> >> >> > _______________________________________________________________________
> >> >> > >> > > > > >> Ken Stone sasami@ otherunicorn@
> >> >> > >> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> >> > >> > > > > >> Australian Miniature Horses & Ponies
> >> >> > <http://www.blaze.net.au/~sasami/>
> >> >> > >> > > > > >>
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > > >------------------------------------
> >> >> > >> > > > > >
> >> >> > >> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> >> > >> > > > > >Yahoo! Groups Links
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > >
> >> >> > _______________________________________________________________________
> >> >> > >> > > > > Ken Stone sasami@ otherunicorn@
> >> >> > >> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> >> > >> > > > > Australian Miniature Horses & Ponies
> >> >> > <http://www.blaze.net.au/~sasami/>
> >> >> > >> > > > >
> >> >> > >> > > >
> >> >> > >> > >
> >> >> > >> >
> >> >> > >>
> >> >> > >
> >> >> > >
> >> >> > >
> >> >> > >
> >> >> > >------------------------------------
> >> >> > >
> >> >> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> >> > >Yahoo! Groups Links
> >> >> > >
> >> >> > >
> >> >> > >
> >> >> > >
> >> >> > _______________________________________________________________________
> >> >> > Ken Stone sasami@ otherunicorn@
> >> >> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> >> >
> >> >>
> >> >
> >> >
> >> >
> >> >
> >> >------------------------------------
> >> >
> >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> >Yahoo! Groups Links
> >> >
> >> >
> >> >
> >> >
> >> _______________________________________________________________________
> >> Ken Stone sasami@ otherunicorn@
> >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-25 by Sean

Still waiting on the alternate LM3900s and the PN4250s I used are here...

http://www.mouser.com/Search/ProductDetail.aspx?R=PN4250Avirtualkey61000000virtualkey610-PN4250A

-Sean
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Looked it all over. Compared it with mine. Can't see anything obviously amiss.
> My thoughts:
> 1) check that the PN4250 are in the correct way. I can see you have them
> according to the overlay, but perhaps the transistors are reversed int he
> package. (all the same, I don't see how this would have any effect on your
> problem.
> 2) I guess it is possible that it is the LM3900 chips themselves that are no
> good. If someone has relabeled CA3401 and sold them as LM3900, you would
> expect trouble, as the CA3401 is only good to 15V, unlike the LM3900 that
> can go up to 30V. They aren't NTE or something like that, are they?
> 3)I can't read the 1n caps, so I can't say they are the right part.
> (0.001uF, 1n, 1000pF).
>
> Ken
>
> >Maybe, slightly better pic of back...
> >https://sphotos-a.xx.fbcdn.net/hphotos-ash4/317422_10151631973766807_174487
> 4777_n.jpg
> >
> >
> >--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >>
> >> Hopefully this works? btw, I also had to use two larger 2.2M resistors
> in the build. One is pulled in the pic (for troubleshooting)
> >>
> >> Thanks -Sean
> >>
> >>
> http://groups.yahoo.com/group/cgs_synth/photos/album/1219515935/pic/list?mod
> e=tn&order=ordinal&start=1&dir=asc
> >>
> >> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> >
> >> > Take some high res photos - IN FOCUS - of both sides so we can look at it.
> >> > Ken
> >> > >Yup, only connected to 1n cap and not using pad T. No shorting when chip
> >> > is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
> >> > checked solder joints and traces many times over. I can't help but think
> >> > it's something else.. maybe a weird transistor or cap or mislabel resistor
> >> > here? btw, same behavior on both LM3900s... extreme heat. Ouch.
> >> > >
> >> > >--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@> wrote:
> >> > >>
> >> > >> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
> >> > There should be no current flow through it. Find out what pin 9 of the
> >> > socket is short circuited to.
> >> > >>
> >> > >> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >> > >> >
> >> > >> > Been testing my voltages (with blown LM3900s removed) btw, pin 9 is
> >> > getting burns on IC socket.
> >> > >> >
> >> > >> > 1) +7.50
> >> > >> > 2) 0
> >> > >> > 3) -7.41
> >> > >> > 4) -14.01
> >> > >> > 5) +3.59
> >> > >> > 6) -0.06
> >> > >> > 7) -14.87
> >> > >> > 8) -0.01
> >> > >> > 9) 0
> >> > >> > 10) -0.10
> >> > >> > 11) -0.06
> >> > >> > 12) +8.06
> >> > >> > 13) -3.34 (stepped), +5.82 (smooth)
> >> > >> > 14) +14.86
> >> > >> >
> >> > >> > Strange voltages I'm getting.
> >> > >> > -Sean
> >> > >> >
> >> > >> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> > >> > >
> >> > >> > > Sorry, that came out as a big garbled mess.
> >> > >> > >
> >> > >> > >
> >> > >> > > 1) +13.54
> >> > >> > > 2) 0
> >> > >> > > 3) -9.23
> >> > >> > > 4) -14.35
> >> > >> > > 5) +11.13
> >> > >> > > 6) -0.113
> >> > >> > > 7) -15
> >> > >> > > 8) -.010
> >> > >> > > 9) 0
> >> > >> > > 10) -.112
> >> > >> > > 11) -.115
> >> > >> > > 12) +13
> >> > >> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
> >> > >> > > 14) +15
> >> > >> > >
> >> > >> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> > >> > > >
> >> > >> > > > So all the voltages read the same on both chips except for pin 13
> >> > which i make a note of :
> >> > >> > > >
> >> > >> > > > 1) +13.54 14) +15
> >> > >> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
> >> > >> > > > 3) -9.23 12) +13
> >> > >> > > > 4) -14.35 11) -.115
> >> > >> > > > 5) +11.13 10) -.112
> >> > >> > > > 6) -0.113 9) 0
> >> > >> > > > 7) -15 8)-.010
> >> > >> > > >
> >> > >> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> > >> > > > >
> >> > >> > > > > Seriously, chip frying is indication of serious power
> routing issues.
> >> > >> > > > >
> >> > >> > > > > With the chips OUT, read the voltages on each pin of the socket,
> >> > then list
> >> > >> > > > > them here.
> >> > >> > > > >
> >> > >> > > > > Ken
> >> > >> > > > >
> >> > >> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
> >> > >> > > > > >I've triple checked component values at this point,replaced
> >> > >> > > > > trannies,ic's,gone over continuity testing and visually
> inspected
> >> > the board
> >> > >> > > > > under a magnifying lens with no luck.
> >> > >> > > > > >
> >> > >> > > > > >There has to be a short or something that i am just not seeing
> >> > because i'm
> >> > >> > > > > getting inconsistent results when i plug it in every time i make
> >> > a change.I
> >> > >> > > > > fried another lm3900 in the smooth section only this time it
> took
> >> > a few
> >> > >> > > > > minutes.I've been able to get a slewed/smoothed signal to
> pass but no
> >> > >> > > > > control over the hold or rate, i've gotten a steady tone from
> >> > plugging the
> >> > >> > > > > cycle into the in of the smooth section but again no control to
> >> > change the
> >> > >> > > > > pitch and now i'm back to were i started with no effect and
> a strong
> >> > >> > > > > negative voltage on the outputs ?
> >> > >> > > > > >
> >> > >> > > > > >I'm gonna take a little break but at this point i'm seriously
> >> > considering a
> >> > >> > > > > do over.
> >> > >> > > > > >
> >> > >> > > > > >Thanks again guys i really appreciate you taking the time to
> >> > offer your
> >> > >> > > > > time and experience !
> >> > >> > > > > >
> >> > >> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> > >> > > > > >>
> >> > >> > > > > >> Been thinkng about this - The problem may also be caused by
> >> > putting a
> >> > >> > > > > >> voltage on the input pins, which are designed for
> current, not
> >> > voltage.
> >> > >> > > > > >> Check nothing is shorted to them. Check your resistor values.
> >> > Maye sure you
> >> > >> > > > > >> haven't installed 15 ohms instead of 1M.
> >> > >> > > > > >>
> >> > >> > > > > >> Ken
> >> > >> > > > > >>
> >> > >> > > > > >> >Will do.Thanks guys!
> >> > >> > > > > >> >I'll report back when i get this working.
> >> > >> > > > > >> >
> >> > >> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> >> > >> > > > > >> <richmolindarius@> wrote:
> >> > >> > > > > >> >>
> >> > >> > > > > >> >> Use a well lit magnified lamp. Especially for that board.
> >> > Hard to find
> >> > >> > > > > >> >> small trace breaks and bad solder joints.
> >> > >> > > > > >> >>
> >> > >> > > > > >> >>
> >> > >> > > > > >> >> [Non-text portions of this message have been removed]
> >> > >> > > > > >> >>
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >> >------------------------------------
> >> > >> > > > > >> >
> >> > >> > > > > >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> > >> > > > > >> >Yahoo! Groups Links
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >> >
> >> > >> > > > > >>
> >> > _______________________________________________________________________
> >> > >> > > > > >> Ken Stone sasami@ otherunicorn@
> >> > >> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> > >> > > > > >> Australian Miniature Horses & Ponies
> >> > <http://www.blaze.net.au/~sasami/>
> >> > >> > > > > >>
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >------------------------------------
> >> > >> > > > > >
> >> > >> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> > >> > > > > >Yahoo! Groups Links
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > >
> >> > _______________________________________________________________________
> >> > >> > > > > Ken Stone sasami@ otherunicorn@
> >> > >> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> > >> > > > > Australian Miniature Horses & Ponies
> >> > <http://www.blaze.net.au/~sasami/>
> >> > >> > > > >
> >> > >> > > >
> >> > >> > >
> >> > >> >
> >> > >>
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >------------------------------------
> >> > >
> >> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> > >Yahoo! Groups Links
> >> > >
> >> > >
> >> > >
> >> > >
> >> > _______________________________________________________________________
> >> > Ken Stone sasami@ otherunicorn@
> >> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> >
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-25 by cg_synth

>Still waiting on the alternate LM3900s and the PN4250s I used are here...

They would appear to be EBC pinout, which means if you put the transistors
in with the D in the same direction as the overlay, they will be backwards.

Ken

>
>http://www.mouser.com/Search/ProductDetail.aspx?R=PN4250Avirtualkey61000000
virtualkey610-PN4250A
>
>-Sean
>
>--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>>
>> Looked it all over. Compared it with mine. Can't see anything obviously
amiss.
>> My thoughts:
>> 1) check that the PN4250 are in the correct way. I can see you have them
>> according to the overlay, but perhaps the transistors are reversed int he
>> package. (all the same, I don't see how this would have any effect on your
>> problem.
>> 2) I guess it is possible that it is the LM3900 chips themselves that are no
>> good. If someone has relabeled CA3401 and sold them as LM3900, you would
>> expect trouble, as the CA3401 is only good to 15V, unlike the LM3900 that
>> can go up to 30V. They aren't NTE or something like that, are they?
>> 3)I can't read the 1n caps, so I can't say they are the right part.
>> (0.001uF, 1n, 1000pF).
>>
>> Ken
>>
>> >Maybe, slightly better pic of back...
>> >https://sphotos-a.xx.fbcdn.net/hphotos-ash4/317422_10151631973766807_174487
>> 4777_n.jpg
>> >
>> >
>> >--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
>> >>
>> >> Hopefully this works? btw, I also had to use two larger 2.2M resistors
>> in the build. One is pulled in the pic (for troubleshooting)
>> >>
>> >> Thanks -Sean
>> >>
>> >>
>> http://groups.yahoo.com/group/cgs_synth/photos/album/1219515935/pic/list?mod
>> e=tn&order=ordinal&start=1&dir=asc
>> >>
>> >> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> >> >
>> >> > Take some high res photos - IN FOCUS - of both sides so we can look
at it.
>> >> > Ken
>> >> > >Yup, only connected to 1n cap and not using pad T. No shorting
when chip
>> >> > is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
>> >> > checked solder joints and traces many times over. I can't help but
think
>> >> > it's something else.. maybe a weird transistor or cap or mislabel
resistor
>> >> > here? btw, same behavior on both LM3900s... extreme heat. Ouch.
>> >> > >
>> >> > >--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@> wrote:
>> >> > >>
>> >> > >> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
>> >> > There should be no current flow through it. Find out what pin 9 of the
>> >> > socket is short circuited to.
>> >> > >>
>> >> > >> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
>> >> > >> >
>> >> > >> > Been testing my voltages (with blown LM3900s removed) btw, pin
9 is
>> >> > getting burns on IC socket.
>> >> > >> >
>> >> > >> > 1) +7.50
>> >> > >> > 2) 0
>> >> > >> > 3) -7.41
>> >> > >> > 4) -14.01
>> >> > >> > 5) +3.59
>> >> > >> > 6) -0.06
>> >> > >> > 7) -14.87
>> >> > >> > 8) -0.01
>> >> > >> > 9) 0
>> >> > >> > 10) -0.10
>> >> > >> > 11) -0.06
>> >> > >> > 12) +8.06
>> >> > >> > 13) -3.34 (stepped), +5.82 (smooth)
>> >> > >> > 14) +14.86
>> >> > >> >
>> >> > >> > Strange voltages I'm getting.
>> >> > >> > -Sean
>> >> > >> >
>> >> > >> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
>> >> > >> > >
>> >> > >> > > Sorry, that came out as a big garbled mess.
>> >> > >> > >
>> >> > >> > >
>> >> > >> > > 1) +13.54
>> >> > >> > > 2) 0
>> >> > >> > > 3) -9.23
>> >> > >> > > 4) -14.35
>> >> > >> > > 5) +11.13
>> >> > >> > > 6) -0.113
>> >> > >> > > 7) -15
>> >> > >> > > 8) -.010
>> >> > >> > > 9) 0
>> >> > >> > > 10) -.112
>> >> > >> > > 11) -.115
>> >> > >> > > 12) +13
>> >> > >> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
>> >> > >> > > 14) +15
>> >> > >> > >
>> >> > >> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
>> >> > >> > > >
>> >> > >> > > > So all the voltages read the same on both chips except for
pin 13
>> >> > which i make a note of :
>> >> > >> > > >
>> >> > >> > > > 1) +13.54 14) +15
>> >> > >> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
>> >> > >> > > > 3) -9.23 12) +13
>> >> > >> > > > 4) -14.35 11) -.115
>> >> > >> > > > 5) +11.13 10) -.112
>> >> > >> > > > 6) -0.113 9) 0
>> >> > >> > > > 7) -15 8)-.010
>> >> > >> > > >
>> >> > >> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> >> > >> > > > >
>> >> > >> > > > > Seriously, chip frying is indication of serious power
>> routing issues.
>> >> > >> > > > >
>> >> > >> > > > > With the chips OUT, read the voltages on each pin of the
socket,
>> >> > then list
>> >> > >> > > > > them here.
>> >> > >> > > > >
>> >> > >> > > > > Ken
>> >> > >> > > > >
>> >> > >> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
>> >> > >> > > > > >I've triple checked component values at this point,replaced
>> >> > >> > > > > trannies,ic's,gone over continuity testing and visually
>> inspected
>> >> > the board
>> >> > >> > > > > under a magnifying lens with no luck.
>> >> > >> > > > > >
>> >> > >> > > > > >There has to be a short or something that i am just not
seeing
>> >> > because i'm
>> >> > >> > > > > getting inconsistent results when i plug it in every time
i make
>> >> > a change.I
>> >> > >> > > > > fried another lm3900 in the smooth section only this time it
>> took
>> >> > a few
>> >> > >> > > > > minutes.I've been able to get a slewed/smoothed signal to
>> pass but no
>> >> > >> > > > > control over the hold or rate, i've gotten a steady tone from
>> >> > plugging the
>> >> > >> > > > > cycle into the in of the smooth section but again no
control to
>> >> > change the
>> >> > >> > > > > pitch and now i'm back to were i started with no effect and
>> a strong
>> >> > >> > > > > negative voltage on the outputs ?
>> >> > >> > > > > >
>> >> > >> > > > > >I'm gonna take a little break but at this point i'm
seriously
>> >> > considering a
>> >> > >> > > > > do over.
>> >> > >> > > > > >
>> >> > >> > > > > >Thanks again guys i really appreciate you taking the time to
>> >> > offer your
>> >> > >> > > > > time and experience !
>> >> > >> > > > > >
>> >> > >> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> >> > >> > > > > >>
>> >> > >> > > > > >> Been thinkng about this - The problem may also be
caused by
>> >> > putting a
>> >> > >> > > > > >> voltage on the input pins, which are designed for
>> current, not
>> >> > voltage.
>> >> > >> > > > > >> Check nothing is shorted to them. Check your resistor
values.
>> >> > Maye sure you
>> >> > >> > > > > >> haven't installed 15 ohms instead of 1M.
>> >> > >> > > > > >>
>> >> > >> > > > > >> Ken
>> >> > >> > > > > >>
>> >> > >> > > > > >> >Will do.Thanks guys!
>> >> > >> > > > > >> >I'll report back when i get this working.
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
>> >> > >> > > > > >> <richmolindarius@> wrote:
>> >> > >> > > > > >> >>
>> >> > >> > > > > >> >> Use a well lit magnified lamp. Especially for that
board.
>> >> > Hard to find
>> >> > >> > > > > >> >> small trace breaks and bad solder joints.
>> >> > >> > > > > >> >>
>> >> > >> > > > > >> >>
>> >> > >> > > > > >> >> [Non-text portions of this message have been removed]
>> >> > >> > > > > >> >>
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >------------------------------------
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >The CGS Modular Synth home page:
http://www.cgs.synth.net/
>> >> > >> > > > > >> >Yahoo! Groups Links
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >> >
>> >> > >> > > > > >>
>> >> > _______________________________________________________________________
>> >> > >> > > > > >> Ken Stone sasami@ otherunicorn@
>> >> > >> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> >> > >> > > > > >> Australian Miniature Horses & Ponies
>> >> > <http://www.blaze.net.au/~sasami/>
>> >> > >> > > > > >>
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > > >------------------------------------
>> >> > >> > > > > >
>> >> > >> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> >> > >> > > > > >Yahoo! Groups Links
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > > >
>> >> > >> > > > >
>> >> > _______________________________________________________________________
>> >> > >> > > > > Ken Stone sasami@ otherunicorn@
>> >> > >> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> >> > >> > > > > Australian Miniature Horses & Ponies
>> >> > <http://www.blaze.net.au/~sasami/>
>> >> > >> > > > >
>> >> > >> > > >
>> >> > >> > >
>> >> > >> >
>> >> > >>
>> >> > >
>> >> > >
>> >> > >
>> >> > >
>> >> > >------------------------------------
>> >> > >
>> >> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> >> > >Yahoo! Groups Links
>> >> > >
>> >> > >
>> >> > >
>> >> > >
>> >> > _______________________________________________________________________
>> >> > Ken Stone sasami@ otherunicorn@
>> >> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> >> >
>> >>
>> >
>> >
>> >
>> >
>> >------------------------------------
>> >
>> >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> >Yahoo! Groups Links
>> >
>> >
>> >
>> >
>> _______________________________________________________________________
>> Ken Stone sasami@... otherunicorn@...
>> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: SSG troubleshoot and weird lm3900 behavior

2013-04-25 by Sean

Great to know... going to fix it tonight. What a relief :o) Ken, you're the best!

Thank again, Sean
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> >Still waiting on the alternate LM3900s and the PN4250s I used are here...
>
> They would appear to be EBC pinout, which means if you put the transistors
> in with the D in the same direction as the overlay, they will be backwards.
>
> Ken
>
> >
> >http://www.mouser.com/Search/ProductDetail.aspx?R=PN4250Avirtualkey61000000
> virtualkey610-PN4250A
> >
> >-Sean
> >
> >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >>
> >> Looked it all over. Compared it with mine. Can't see anything obviously
> amiss.
> >> My thoughts:
> >> 1) check that the PN4250 are in the correct way. I can see you have them
> >> according to the overlay, but perhaps the transistors are reversed int he
> >> package. (all the same, I don't see how this would have any effect on your
> >> problem.
> >> 2) I guess it is possible that it is the LM3900 chips themselves that are no
> >> good. If someone has relabeled CA3401 and sold them as LM3900, you would
> >> expect trouble, as the CA3401 is only good to 15V, unlike the LM3900 that
> >> can go up to 30V. They aren't NTE or something like that, are they?
> >> 3)I can't read the 1n caps, so I can't say they are the right part.
> >> (0.001uF, 1n, 1000pF).
> >>
> >> Ken
> >>
> >> >Maybe, slightly better pic of back...
> >> >https://sphotos-a.xx.fbcdn.net/hphotos-ash4/317422_10151631973766807_174487
> >> 4777_n.jpg
> >> >
> >> >
> >> >--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >> >>
> >> >> Hopefully this works? btw, I also had to use two larger 2.2M resistors
> >> in the build. One is pulled in the pic (for troubleshooting)
> >> >>
> >> >> Thanks -Sean
> >> >>
> >> >>
> >> http://groups.yahoo.com/group/cgs_synth/photos/album/1219515935/pic/list?mod
> >> e=tn&order=ordinal&start=1&dir=asc
> >> >>
> >> >> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> >> >
> >> >> > Take some high res photos - IN FOCUS - of both sides so we can look
> at it.
> >> >> > Ken
> >> >> > >Yup, only connected to 1n cap and not using pad T. No shorting
> when chip
> >> >> > is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
> >> >> > checked solder joints and traces many times over. I can't help but
> think
> >> >> > it's something else.. maybe a weird transistor or cap or mislabel
> resistor
> >> >> > here? btw, same behavior on both LM3900s... extreme heat. Ouch.
> >> >> > >
> >> >> > >--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@> wrote:
> >> >> > >>
> >> >> > >> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
> >> >> > There should be no current flow through it. Find out what pin 9 of the
> >> >> > socket is short circuited to.
> >> >> > >>
> >> >> > >> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >> >> > >> >
> >> >> > >> > Been testing my voltages (with blown LM3900s removed) btw, pin
> 9 is
> >> >> > getting burns on IC socket.
> >> >> > >> >
> >> >> > >> > 1) +7.50
> >> >> > >> > 2) 0
> >> >> > >> > 3) -7.41
> >> >> > >> > 4) -14.01
> >> >> > >> > 5) +3.59
> >> >> > >> > 6) -0.06
> >> >> > >> > 7) -14.87
> >> >> > >> > 8) -0.01
> >> >> > >> > 9) 0
> >> >> > >> > 10) -0.10
> >> >> > >> > 11) -0.06
> >> >> > >> > 12) +8.06
> >> >> > >> > 13) -3.34 (stepped), +5.82 (smooth)
> >> >> > >> > 14) +14.86
> >> >> > >> >
> >> >> > >> > Strange voltages I'm getting.
> >> >> > >> > -Sean
> >> >> > >> >
> >> >> > >> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> >> > >> > >
> >> >> > >> > > Sorry, that came out as a big garbled mess.
> >> >> > >> > >
> >> >> > >> > >
> >> >> > >> > > 1) +13.54
> >> >> > >> > > 2) 0
> >> >> > >> > > 3) -9.23
> >> >> > >> > > 4) -14.35
> >> >> > >> > > 5) +11.13
> >> >> > >> > > 6) -0.113
> >> >> > >> > > 7) -15
> >> >> > >> > > 8) -.010
> >> >> > >> > > 9) 0
> >> >> > >> > > 10) -.112
> >> >> > >> > > 11) -.115
> >> >> > >> > > 12) +13
> >> >> > >> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
> >> >> > >> > > 14) +15
> >> >> > >> > >
> >> >> > >> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> >> > >> > > >
> >> >> > >> > > > So all the voltages read the same on both chips except for
> pin 13
> >> >> > which i make a note of :
> >> >> > >> > > >
> >> >> > >> > > > 1) +13.54 14) +15
> >> >> > >> > > > 2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
> >> >> > >> > > > 3) -9.23 12) +13
> >> >> > >> > > > 4) -14.35 11) -.115
> >> >> > >> > > > 5) +11.13 10) -.112
> >> >> > >> > > > 6) -0.113 9) 0
> >> >> > >> > > > 7) -15 8)-.010
> >> >> > >> > > >
> >> >> > >> > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> >> > >> > > > >
> >> >> > >> > > > > Seriously, chip frying is indication of serious power
> >> routing issues.
> >> >> > >> > > > >
> >> >> > >> > > > > With the chips OUT, read the voltages on each pin of the
> socket,
> >> >> > then list
> >> >> > >> > > > > them here.
> >> >> > >> > > > >
> >> >> > >> > > > > Ken
> >> >> > >> > > > >
> >> >> > >> > > > > >Thanks again Ken, and Rich for all the helpful suggestions.
> >> >> > >> > > > > >I've triple checked component values at this point,replaced
> >> >> > >> > > > > trannies,ic's,gone over continuity testing and visually
> >> inspected
> >> >> > the board
> >> >> > >> > > > > under a magnifying lens with no luck.
> >> >> > >> > > > > >
> >> >> > >> > > > > >There has to be a short or something that i am just not
> seeing
> >> >> > because i'm
> >> >> > >> > > > > getting inconsistent results when i plug it in every time
> i make
> >> >> > a change.I
> >> >> > >> > > > > fried another lm3900 in the smooth section only this time it
> >> took
> >> >> > a few
> >> >> > >> > > > > minutes.I've been able to get a slewed/smoothed signal to
> >> pass but no
> >> >> > >> > > > > control over the hold or rate, i've gotten a steady tone from
> >> >> > plugging the
> >> >> > >> > > > > cycle into the in of the smooth section but again no
> control to
> >> >> > change the
> >> >> > >> > > > > pitch and now i'm back to were i started with no effect and
> >> a strong
> >> >> > >> > > > > negative voltage on the outputs ?
> >> >> > >> > > > > >
> >> >> > >> > > > > >I'm gonna take a little break but at this point i'm
> seriously
> >> >> > considering a
> >> >> > >> > > > > do over.
> >> >> > >> > > > > >
> >> >> > >> > > > > >Thanks again guys i really appreciate you taking the time to
> >> >> > offer your
> >> >> > >> > > > > time and experience !
> >> >> > >> > > > > >
> >> >> > >> > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> >> > >> > > > > >>
> >> >> > >> > > > > >> Been thinkng about this - The problem may also be
> caused by
> >> >> > putting a
> >> >> > >> > > > > >> voltage on the input pins, which are designed for
> >> current, not
> >> >> > voltage.
> >> >> > >> > > > > >> Check nothing is shorted to them. Check your resistor
> values.
> >> >> > Maye sure you
> >> >> > >> > > > > >> haven't installed 15 ohms instead of 1M.
> >> >> > >> > > > > >>
> >> >> > >> > > > > >> Ken
> >> >> > >> > > > > >>
> >> >> > >> > > > > >> >Will do.Thanks guys!
> >> >> > >> > > > > >> >I'll report back when i get this working.
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> >> >> > >> > > > > >> <richmolindarius@> wrote:
> >> >> > >> > > > > >> >>
> >> >> > >> > > > > >> >> Use a well lit magnified lamp. Especially for that
> board.
> >> >> > Hard to find
> >> >> > >> > > > > >> >> small trace breaks and bad solder joints.
> >> >> > >> > > > > >> >>
> >> >> > >> > > > > >> >>
> >> >> > >> > > > > >> >> [Non-text portions of this message have been removed]
> >> >> > >> > > > > >> >>
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >------------------------------------
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >The CGS Modular Synth home page:
> http://www.cgs.synth.net/
> >> >> > >> > > > > >> >Yahoo! Groups Links
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >> >
> >> >> > >> > > > > >>
> >> >> > _______________________________________________________________________
> >> >> > >> > > > > >> Ken Stone sasami@ otherunicorn@
> >> >> > >> > > > > >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> >> > >> > > > > >> Australian Miniature Horses & Ponies
> >> >> > <http://www.blaze.net.au/~sasami/>
> >> >> > >> > > > > >>
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > > >------------------------------------
> >> >> > >> > > > > >
> >> >> > >> > > > > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> >> > >> > > > > >Yahoo! Groups Links
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > > >
> >> >> > >> > > > >
> >> >> > _______________________________________________________________________
> >> >> > >> > > > > Ken Stone sasami@ otherunicorn@
> >> >> > >> > > > > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> >> > >> > > > > Australian Miniature Horses & Ponies
> >> >> > <http://www.blaze.net.au/~sasami/>
> >> >> > >> > > > >
> >> >> > >> > > >
> >> >> > >> > >
> >> >> > >> >
> >> >> > >>
> >> >> > >
> >> >> > >
> >> >> > >
> >> >> > >
> >> >> > >------------------------------------
> >> >> > >
> >> >> > >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> >> > >Yahoo! Groups Links
> >> >> > >
> >> >> > >
> >> >> > >
> >> >> > >
> >> >> > _______________________________________________________________________
> >> >> > Ken Stone sasami@ otherunicorn@
> >> >> > Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> >> >
> >> >>
> >> >
> >> >
> >> >
> >> >
> >> >------------------------------------
> >> >
> >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> >Yahoo! Groups Links
> >> >
> >> >
> >> >
> >> >
> >> _______________________________________________________________________
> >> Ken Stone sasami@ otherunicorn@
> >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>

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