--- In chromapolaris@yahoogroups.com, "Paul D. DeRocco" <pderocco@...> wrote:

>
> > From: wasteking1
> >
> > you were right--i was testing with the master volume slider--- using the
> > assignable volume it cuts out at about 40% of the way up . At the risk of
> > sounding even more stupid-- i was wondering how i would check for negative
> > voltage --crossing pin 7 with what? ground? and my simple anaolg needle
> > radioshak meter showed +3 volts when i crossed from the battery
> > to pin 7 on all zx03 chips. [ but i could try swapping Zxo3
> > chips if they are the likely source] ..i assume
> > that voices 1-6 correspond to chips numbered z2o3-z703 in the 'X'
> > place . of
> > course that places chip Z203 under the output board requiring
> > unscrewing the
> > whole main circuitboard.
>
> To measure negative voltages with an analog meter, just connect the positive
> input to the meter to ground somewhere, and use the negative input to probe
> the op-amp outputs; the negative voltages will show up as positive values on
> the meter. If you have a digital meter, then it'll have a minus sign.
>
> If the chips are socketed, then, yes, swapping them is a good way to find
> bad chips. It's unlikely to be the capacitors, because leaky capacitors pull
> the voltage toward ground, not toward the minus rail.
>
> --
>
> Ciao, Paul D. DeRocco
> Paul mailto:pderocco@...
>

well i made a mess now
i first tried swapping all 5 chips (01.02,03,04,05) in the sample and hold area betwwen the Z2 (voice 1) and Z6 (voice 5)-- no change in the touch sensitivity problem. so i had this great fear that the voices were inverted and maybe voice 1 was actually the Z7 row(actually voice 6)...so i pulled out a chip to see if voice 6 would or wouldnt work-- it didnt sound so i put the chip back having confirmed that it was indeed voice 6... but now voice 6 is all messed up-- it plays only a click on all keys till the c sharp in the 4th octave then itplays a loud tone (but not the patch) then above this i get just a quiet high pitch tone on all notes above. I tried switching ALL chips between voice 5 and 6 but no change -- i seem to have killed voice 6 and still have the problem with voice 1-- any great ideas here??