SAE X15A

Hello im stuck on a problem i cant seem to figure out, I have a SAE X15A power amplifier i purchased as is. It stated right channel was blowing fuse, I fixed that but now I have this weird thing going on with the left side. After powering up everythings good, but after a few seconds the left power meter goes crazy up and down over and over with no input plugged in.Ive replaced all 4 of the LM324N on the meter board for that channel and replaced all the caps, I also found a NTE transistor on the input board and replaced it with factory MPSA56.I tested every component on the input board and power board its all checks out.there is a opamp on the meter board marked 11-0168 SAE P/N and RT7651 but cannot find any info please help thank you all very much.