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

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Subject: Re: [PolySix] RE: Lots of pots not working

From: Bob Grieb <bobgrieb@yahoo.com>
Date: 2014-01-08

Josh,

    I think LED 5 means that when the CPU is trying to select the Effects pot,
its actually selecting one of the pots that is set to the middle position.
Try turning all of the front panel pots when in the DAC cal position and see
which ones make the illuminated LEDs move.   That will give us a clue as
to how the mux control lines are screwed up.

      Bob


From: "josh.nursing@gmail.com" <josh.nursing@gmail.com>
To: PolySix@yahoogroups.com
Sent: Wednesday, January 8, 2014 8:52 AM
Subject: Re: [PolySix] RE: Lots of pots not working, MG, VCF, EG.

 
Replacement Zener found and installed at D2, continuity tested around it, part of calibration procedure re-done, when calibrating the DAC, LEDs 1 & 5 are still on no matter what.

Spent a good time reflowing and checking KLM-371 too.

So now it feels like I am nearing a complete repair since the Polysix sounds really good and clean, and when I do get control over the pots, it's much fun.

Somehow the signals get garbled up, so if swapping the two new 4051s does not help, I will also try a swap of the CPU as well as testing each 4051 individually on a breadboard.

Yash