C32 Left channel level drops significantly when Eq is engaged

[sabrefencer]

I was evaluating a C32 for purchase and it was fine with the Eq defeated. When eq was engaged, the left channel volume went way down. Any ideas? Could it be the ribbon cables? Anyone had any experience with the aftermarket cables sold on Ebay?

 

[kevzep]

Might want to clean the switch first, more likely that than the ribbon cable.
The problem with the ribbon cables is they de-laminate, which does not cause any audio drop out type issues.

 

[MikeRam]

I had a similar issue with my C32. My left side would go out when the EQ was engaged and it turned out to be the opamp IC's 601 and 603. They are part # 133-043 on the C32 service manual. Changing out IC 601 and 603 with 926-LF356N/NOPB chips fixed the EQ issue. After that it worked both bypassed and engaged.

Since you still get some sound, your chips might still be good. I would pop out the IC's and then press them back in to make sure all pins have a good connection. If that doesn't make a difference, swap them with the ones on the right side and see if the problem follows the chips.

Here is a picture of the EQ board and IC's 601 and 603 are the two circled on the left side of the board.

 

[twiiii]

I had a similar issue and it was the record equalization switch. The tech at AC had to disassemble and rebuild the switch physically. Thanks again to Ryan and Steve at Audio Classics.

 

[Searing75]

Clean all switches. I recapped, and updated all ic’s In mine. I also replaced most of the ribbon cables with the kit from eBay. Great kit! I would recommend the ribbon kit, replacing all electrolytic caps, and all Ic’s.