PC5032 is the one for the power amp. I'd start by pushing on a few things on the power amp board to see if anything is loose.
Do you feel confident in working on an amp that is plugged in and turned on? There are things inside the amp that can hurt you, so if you don't feel confident, please refer servicing to a qualified tech.
Alternatively you can pull out the board and inspect the soldering on the bottom side without having it plugged in. How are your soldering skills?