Discussion about the Korg PolySix synthesizer

I don’t know whether the coupling between traces on the board is conductive or inductive/capacitive after battery damage, but it certainly is real and can be very difficult to track down. You did a excellent work to find this. I don’t think I’ve seen this problem on an effects board but it used to be fairly common when trying to repair old KLM-367 battery damaged boards. I gave up and always build new clone boards now. 
Don Backshall

From: mpe1969@tpg.com.au [PolySix] 
Sent: Monday, June 4, 2018 7:47 AM
To: PolySix@yahoogroups.com 
Subject: [PolySix] Re: polysix effect issue

  
Thanks for the advice. Firstly I tested this board again in a working polysix and the volume was still an issue (therefore it had to be on the elm 368 effects board). I checked one cv at a time. The effects speed voltage was crossing to IC21 pin7( patch level), altering the voltage. This board did have battery damage which I had previously cleaned. Not knowing what else to check I re-cleaned the battery damaged tracks. This gave a slight improvement. I then took out my etcher and etched inbetween all the damaged tracks and this fixed my problem. I initially was trying to remove battery damage, but I gather now that the battery leakage is also conductive. Is this correct? 

I've tested the keyboard twice tonight and it is still working. The voltage is constant on IC21 pin7 and not affected by the speed dial. I'll test it again tomorrow night.
Once again thanks. Hope this helps anyone in a similar situation.