Archive of the former Yahoo!Groups mailing list: Discussion about the Korg PolySix synthesizer

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Subject: Re: Trying to Restore a P6.

From: 7zlwncpbis4x22jwvkd4oc5hzu2njcsjeup42is6@yahoo.com
Date: 2016-08-31

Thanks again for your patience and guidance on this, Bob. I'm going to get this working right eventually.
    I see no voltage change on pin 1 of IC 14, and pin 3 exhibits odd behavior, in which putting a probe on it seems to make the voltage rise or fall to settle around 12.8V. The voltage at pin 2 rarely rises above 3V, due to the fall-off in voltage I see on some of the controls, so perhaps I'm seeing the V at pin one due to the fact that the - input is always less than the + input.
    Also, I'm seeing a constant 4.97V on pins 3 and 4 of IC17, which seems odd for it's outputs considering it's function, and what is going into it. I bought some extra 4011s tho, so not a problem to swap out, but please clue me in if I am misunderstanding the circuit.
   And, I will wait to see how IC10 reacts after installing a new IC18, Those connections check out continuity-wise, and I get what you are saying about feedback circuits.
    First I want to pull the board and make sure I didn't do something stupid on the bottom while correcting bad traces, that might have caused the 5V line to get crossed.