Need tools? Here's a video showing what I use (with links!): https://www.youtube.com/watch?v=MLK649c1_fM
This Pioneer SA-8100 appeared to be working just fine with no issues. But after listening for some time, the power amp became wildly unstable and put the amp right into protection! After that was fixed, it received a good amount of preventative maintenance to bring it back up to speed.