Zapco Z-2KD Amplifier

Best I can do it appears to be a 3S board.
 

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Remove all of the outputs that are being driven by that side of the driver board and reinstall Q7 and Q11. Do you still have r-r oscillation on the other bank?

Is R13 within tolerance? Have you confirmed that the other resistors in that area of the driver board are within tolerance.

Are Q7 and 11 new?
 
I bumped up against one of the output inductors and noticed all outputs are doing what’s pictured. Yes Q7 & 11 are new and R13 reads 999ohms. It will take me sometime to remove all the outputs.
 

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