After testing most everything on the board and deciding everything I tested was fine, I decided to throw it back in for testing and it worked! I did not push it but it powered up fine and responded to input the appropriate output. So I added the rest of my screws and was going to run it through some testing. I powered up again and immediately after hitting the power switch, I got a very loud, 60-100hz signal from the woofer. The kind of noise that makes you run for the power switch. Because the noise was instantaneous, I knew it was not waiting for power up from the preamp board, there was something dead wrong in the amp and that was confirmed after testing with a known good amp.
SOOO, clicking or popping noise went back to fine, then to super loud noise. I am wondering if this tone is actually line frequency or 60hz which might indicate the filter caps BUT all the caps look great and are 10yo. I think in every situation where caps have been bad, they show a sign. Any leads here? Controllers for the mosfets? caps? output or PS?