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
under a magnifying lens with no luck.
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 ?
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
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.trannies,ic's,gone over continuity testing and visually inspected the board
>I've triple checked component values at this point,replaced
under a magnifying lens with no luck.
>getting inconsistent results when i plug it in every time i make a change.I
>There has to be a short or something that i am just not seeing because i'm
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 ?
>do over.
>I'm gonna take a little break but at this point i'm seriously considering a
>time and experience !
>Thanks again guys i really appreciate you taking the time to offer your
>_______________________________________________________________________
>--- 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/>