I have a Rotel RB-9808X power amp that has worked fine for years.
Suddenly it makes a huge buzzing out of either speaker. I took the
cover off, but saw no obviously loose items.

When I connect a speaker and plug in an interconnect, the buzz starts.
When I tap the exposed other end of the interconnect, it makes a loud
popping sound. But when I touch the chassis or lean on it, the buzzing
gets quieter.

What gives? Some kind of ground thing? But there's no explicit
"ground" connector on the unit, and it's worked fine for a long time.

Thanks for your thoughts.

Ellis Weiner