> From: wasteking1To measure negative voltages with an analog meter, just connect the positive
>
> 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.
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@...