Yamaha M1532 Direct Out Help

[Ifudontlikebees]

Hello everyone! I recently wired up 8 balanced direct outs for a friend’s Yamaha M1532 using CAPI ea2623 like out transformers. I took the direct out signal from the 100 ohm resistor directly before the pan pot and jumpered it to the unused pin 4 of connector C3. That then goes to the input of the transformer and then to the direct out. The issue I’m having is on channel 4, the direct out works for a second and then goes away really quickly. When it goes away the buss routing stops working for channel 4 too. When I remove the jumper wire, the module works as it should and the buss routing works again. What could be happening? Am I missing something here? Thanks for all the help in advance, here’s a link to the schematic. Input module is on page 13 and 14.
https://www.vintageshifi.com/repertoire-pdf/pdf/telecharge.php?pdf=Yamaha-M-1532-Service-Manual.pdf

 

[Bo Deadly]

Sounds like a bad ground connection and you're getting a DC offset. Look at the DC voltage with a meter at various points. Note if touching the meter probe to the circuit changes anything. If it does, that means there's a tiny leakage current causing a DC offset and it doesn't have a drain path to ground. All points around the pan pot should be DC 0V.

 

[Ifudontlikebees]

If there was a dc offset wouldn’t that cause the channel to not work at all? It only works when the jumper cable isn’t there, when I install the jumper it stops working.

 

[Ifudontlikebees]

Today all channels worked fine except for 4, started tracking and one by one they all cut out on the direct out and buss assign completely. They still work from the unbalanced patch out but do not work from direct out or any busses.