I picked one up a few years back that had all these problems and replaced 4013 and 4556 and everybody was happy again. Since the 4013 has changed since '82, solder a 100k resistor from pin 3 to pin 7.
--- In Simmons_Drums@yahoogroups.com, "philmurr" <philmurr@...> wrote:
>
> As the LED's are driven by IC2 and IC3, I'd definitely suspect one of them. IC3 is just inverting the outputs from IC2 so I think you're going to be correct with IC2.
>
> First of all I'd check that the solder connections for power to both chips are ok (14556 - pins 8/16 & 4011 - pins 7/14)
>
> --- In Simmons_Drums@yahoogroups.com, jesper <jesper@> wrote:
> >
> > philmurr skrev 2013-03-03 20:11:
> > > I'm very happy my IV is working, next up is the SDS-V...
> >
> > Speaking of which...
> >
> > Can the tech guys here enlighten me regarding the program selector
> > switches? I _guess_ the four switches end up at the same IC which opens
> > the selected path... My hihat card works great upon startup if I stay
> > with the factory preset. If I choose anything else it turns weird.
> > Sometimes it plays some odd form of mix of all the presets but mostly
> > it's just a lame and dull sound coming out. The LEDs either light up all
> > or none. After fiften minutes or so it works as it should. It might be a
> > bad soldering joint since heat might help...
> >
> > I dug out the schematics and looking at that crappy copy it looks as if
> > the IC2 (14556) might be the culprit. IC1 is a 4013 btw. Any input from
> > you soldering guys?
> >
> > --
> > electronically yours, jesper
> >
> > - -- --- ---- ----- ---- --- -- -
> > www.electronic-obsession.se
> >
>