Check the 4.7K pullup resistor and the diodes and resistors around the comparator. Maybe something is not connected on the pcb. The logic probe could be acting as a pullup possibly.
Bob
Bob
From: "josh.nursing@gmail.com" <josh.nursing@gmail.com>
To: PolySix@yahoogroups.com
Sent: Monday, January 6, 2014 9:49 AM
Subject: [PolySix] RE: Lots of pots not working, MG, VCF, EG.
To: PolySix@yahoogroups.com
Sent: Monday, January 6, 2014 9:49 AM
Subject: [PolySix] RE: Lots of pots not working, MG, VCF, EG.
Funny, I used the logic probe on CPU pin 1, and suddenly I get control over Cutoff, Res and EG Intensity (but it's flaky, as sometimes it happens).
Nothing changed, except the keyboard got disconnected and reconnected.