Discussion about the Korg PolySix synthesizer

Okay, I've checked everything on the voice and here are the discrepencies. There is -1.2V at the junction of R218, R217, C50, and IC 35 pin 1. There is -1.2V across R217 to IC24 pin 1. There is also -1.2V at IC35 pin 2 and across the series of resistors connected to that pin from R141, R142, R143, R135 and the base of Q6.

When I hit a key to trigger this voice, D10 lights and the -1.2V on IC35 pins 1 and 2 goes up to -0.9V.

I removed IC35 from the socket (with the synth off of course) and performed additional measurements. With no IC in the socket I get -5V on pin 1 and a few mV on pin 2.

I'm not sure what to make of all this.

Thanks for any help.

--- In PolySix@yahoogroups.com, Andrew Jury <andy@...> wrote:
>
> Oh dear! Guess you are going to have to make exhaustive comparative checks
> between working and the non-working voice to get to the bottom of this one.
> It would be interesting at this point to ensure C50 is OK and that the
> filter cut off bias voltage at pin 13 of IC32 doesn¹t vary to wildly from
> the others.
> 
> Cheers,
> Andy