Swap the LF353 IC. See if the fault moves with the IC or stays where it is.
Swap the transistors with a new set.
Ken
the fall pot past about 2 o'clock it will stop cycling.The led flashes at
about 1 second intervals regardless of were i position the pot as long as
it's past the 2 o'clock point but when i'm measuring the voltage on the out
it behaves how you would expect (at it's furthest cw setting it takes about
2-3 minutes to fully drop to zero) as long as i stay cw of 2 o'clock.
transistors.
will be helpful.
ohmmeter, and I check every single trace for continuity. The traces on these
boards are somewhat fragile, especially if you use lead free solder (which
requires higher temperatures). Just be patient and you can get through the
whole thing in an hour or two. Whenever I've had a DUSG failure, this has
found the problem for me.
slow self cycling.It needs a trigger to start this but does not sync with
the trigger at all.As soon as i back off to about 2-3 o'clock it stops.
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
Swap the transistors with a new set.
Ken
>you for the useful tool.
>Ok, i tried the suggestion Gary gave me and unfortunately no luck but thank
>happening and maybe someone can have an idea as to what could be acting up.
>I'm completely in the dark at this point so i want to explain whats
>triggers or signal input.While cycling if i drop the voltage by decreasing
>It will self cycle but only at it's own fixed pace and does not react to
the fall pot past about 2 o'clock it will stop cycling.The led flashes at
about 1 second intervals regardless of were i position the pot as long as
it's past the 2 o'clock point but when i'm measuring the voltage on the out
it behaves how you would expect (at it's furthest cw setting it takes about
2-3 minutes to fully drop to zero) as long as i stay cw of 2 o'clock.
>It also outputs a pulse at the end of cycle.everything seems to be the same, even the voltages on all the ic's and
>
>I've checked every single thing i can think of against the working half and
transistors.
>and it's very difficult to tell if you have a nice joint so this technique
>Thanks for all the help and suggestions so far !
>
>-Tony
>--- In cgs_synth@yahoogroups.com, "adematteo" wrote:
>>
>> Thanks Gary i'll give that a shot.Your right i did use lead free solder
will be helpful.
>>technique I've found that seems to help quite a lot.
>> Thanks Ken but i've checked the wiring so many times i have it memorized.
>>
>> I'll report back when i get this bugger working.
>>
>> Tony
>>
>> --- In cgs_synth@yahoogroups.com, "Mongo" wrote:
>> >
>> > I have had trouble getting DUSGs to work as well, and there is a
>> >traces. I then sit down with that page, a highlighter, the pc board, and an
>> > I print out the picture Ken has on the webpage that shows the PC board
ohmmeter, and I check every single trace for continuity. The traces on these
boards are somewhat fragile, especially if you use lead free solder (which
requires higher temperatures). Just be patient and you can get through the
whole thing in an hour or two. Whenever I've had a DUSG failure, this has
found the problem for me.
>> >hasn't helped a bit ;-)
>> > That being said, I'm troubleshooting a friend's VCS right now, and this
>> >in the future searches better to have a few problems in 1 thread.
>> > Anyway, give that a try. Chances are you will find an open trace.
>> >
>> > Gary
>> >
>> >
>> > --- In cgs_synth@yahoogroups.com, "adematteo" wrote:
>> > >
>> > > Not sure if this is the best way to do this ? but figured if someone
>> > >and the other not working at all as expected.
>> > > Anyhow, i have 1 (1/2 of the board) of my dusg's working perfectly
>> > > The problem is no recognition of a trigger input or signal in forthat matter unless i have the fall pot full cw then it seems to go into a
slow self cycling.It needs a trigger to start this but does not sync with
the trigger at all.As soon as i back off to about 2-3 o'clock it stops.
>> > >advice !
>> > > These are the things i have checked/verified against the working half:
>> > >
>> > > -All ic;s getting and sending the same voltages as working half
>> > > -Diode orientations
>> > > -resitor values
>> > > -Transistor orientation,proper part,voltages the same as working half
>> > > -continuity through path of trig in to output
>> > > -checked for solder bridges
>> > >
>> > > I'm out of ideas so i will really appreciate it if someone has some
>> > >in a close 2nd. :D
>> > > Thanks, Tony
>> > >
>> > > --- In cgs_synth@yahoogroups.com, richmolindarius@ wrote:
>> > > >
>> > > > Fully agreed. The USG is my fave by far with the SSG following up
>> > > >DUSG seems
>> > > > On 2012-10-11, at 12:06 AM, Stephen Richards wrote:
>> > > >
>> > > > > My all time favourite Serge function block , DUSG rocks.
>> > > > >
>> > > > > ________________________________
>> > > > > From: Rico Loverde
>> > > > > To: cgs_synth@yahoogroups.com
>> > > > > Sent: Thursday, October 11, 2012 1:51 PM
>> > > > > Subject: Re: [cgs_synth] Re: CGS114 DUSG problems/troubleshooting
>> > > > >
>> > > > > awesome!!!
>> > > > >
>> > > > > On Wed, Oct 10, 2012 at 7:26 PM, ch1nard wrote:
>> > > > >
>> > > > > > **
>> > > > > >
>> > > > > >
>> > > > > >
>> > > > > > okay awesome, that was totally it
>> > > > > >
>> > > > > > Now other than the fact that i have the pots wired backwards
>> > > > > > functional!and 2N3906)
>> > > > > >
>> > > > > > --- In cgs_synth@yahoogroups.com, "ch1nard" wrote:
>> > > > > > >
>> > > > > > > ah yes, you appear to be correct good sir :)
>> > > > > > > this would be reverse orientation for all trannies? (2N3904
>> > > > > > >if that
>> > > > > > > i will switch them around after i get home from work and see
>> > > > > > fixes things up.i pooched
>> > > > > > >
>> > > > > > > might need to hit up the parts store on the way home in case
>> > > > > > any of them from being in backwardshad people
>> > > > > > >
>> > > > > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> > > > > > > >
>> > > > > > > > Also make sure you are using the right sort of tranny! I
>> > > > > > withwrong sort of
>> > > > > > > > this problem on another project - and they had used the
>> > > > > > tranny.without making
>> > > > > > > >
>> > > > > > > > >Are the trannies situated like the silk screen on the pcb or
>> > > > > > reversed? They
>> > > > > > > > >should be reversed.
>> > > > > > > > >
>> > > > > > > > >
>> > > > > > > > >
>> > > > > > > > >On Tuesday, October 9, 2012, ch1nard wrote:
>> > > > > > > > >
>> > > > > > > > >> **
>> > > > > > > > >>
>> > > > > > > > >>
>> > > > > > > > >> Okay, i have been staring at this for almost a week
>> > > > > > anyfiguring
>> > > > > > > > >> progress so its time to start asking around for help on
>> > > > > > out whatconstantly.
>> > > > > > > > >> might be wrong with my DUSG build
>> > > > > > > > >>
>> > > > > > > > >> I am running this off +/-15v power supply and i have all the
>> > > > > > connections
>> > > > > > > > >> appear to be correct with no magic smoke escaping
>> > > > > > > > >>
>> > > > > > > > >> What is happening is that the output lights are lit up
>> > > > > > > > >> When i hook it up to a scope it appears that both halvesare cycling
>> > > > > > > > >> (triangle) at about only 300mV p/pis still a
>> > > > > > > > >> -fiddling with the rise/fall gives minor variations but
>> > > > > > > > >> triangle. (never hits saw or ramp)as fiddling
>> > > > > > > > >> -feeding LFO into VC in shows the same minor variances
>> > > > > > withthere were a
>> > > > > > > > >> the rise/fall knobs. bipolar control seems to work
>> > > > > > > > >> -feeding a signal IN combines the signal with this triangle
>> > > > > > oscillation
>> > > > > > > > >> -trig and end do nothing
>> > > > > > > > >>
>> > > > > > > > >> now everything 'appears' to be wired up correctly and
>> > > > > > couplethe wiring
>> > > > > > > > >> of lifted pads that i was able to jumper patch around.
>> > > > > > > > >> building this as part of a 'best of cgs' BOG panel, so
>> > > > > > is wellTL072's and
>> > > > > > > > >> documented.
>> > > > > > > > >>
>> > > > > > > > >> I have verified +/- voltage being delivered to all the
>> > > > > > > > >> verified + voltage for the LM3900'sand 2N3906)
>> > > > > > > > >> ground appears to be delivered as well.
>> > > > > > > > >> all the trans are correct value and orientation (2N3904
>> > > > > > wheretonight...
>> > > > > > > > >> applicable
>> > > > > > > > >>
>> > > > > > > > >> Anyways, eyes are too tired to look at this anymore
>> > > > > > > > >> time to smoke a bowl and watch some doctor who._______________________________________________________________________
>> > > > > > > > >>
>> > > > > > > > >>
>> > > > > > > > >>
>> > > > > > > > >
>> > > > > > > > >
>> > > > > > > > >--
>> > > > > > > > >________________
>> > > > > > > > >rico loverde
>> > > > > > > > >415.596.6255
>> > > > > > > > >ricoloverde.com
>> > > > > > > > >
>> > > > > > > > >
>> > > > > > > > >[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
>> > > > > > > > Australian Miniature Horses & Ponies
>> > > > > >
>> > > > > > > >
>> > > > > > >
>> > > > > >
>> > > > > >
>> > > > > >
>> > > > >
>> > > > > --
>> > > > > ________________
>> > > > > rico loverde
>> > > > > 415.596.6255
>> > > > > ricoloverde.com
>> > > > >
>> > > > > [Non-text portions of this message have been removed]
>> > > > >
>> > > > > ------------------------------------
>> > > > >
>> > > > > The CGS Modular Synth home page: http://www.cgs.synth.net/
>> > > > > Yahoo! Groups Links
>> > > > >
>> > > > > [Non-text portions of this message have been removed]
>> > > > >
>> > > > >
>> > > >
>> > > >
>> > > > [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/>