JP-8000 No sound, even after Cap change

I’ve replaced all the caps on the main board with no issues (there was one bad cap, the large one) along with a new battery. The volume contiunued to be low. I then followed that by replacing the caps on the audio board, I noticed an IC had been changed. I handed it over to my father who is a repair technician and wanted he to replace all the IC’s. He did and found that the voltages are correct everywhere but cant get any sound? The power supply is fine the keys are fine. All the lights operate correctly and switch normally. Just no sound. I have a feeling I got a bad IC from Digitech. Has anyone had something like this happen. I feel like this thing should be playing better than ever right now.

It sounds like it may be a faulty op amp in the output circuit. This may be a part on the jack board (but I am not where I can check a service manual right now, so I’m not sure the jack board has any op amps…)

There are, and They have been replaced with new ones but it seems that one of the new ones are bad from Digitech. Going back to replace each again. One at a time with the old ones.

According the the manual, it should be the C4570HA. I replaced it but the source was from England and he was the only vendor that had it new…and it was.