A lot of things to do to this one. I opened it up and here’s what I found:

Loose from its holder and disconnected filter capacitor!

Missing power resistor!

This is that missing resistor, loose and found on the other side of the cabinet!

And a bad solder job at a replaced power cord, which was also loose from the back plate:

(look at those solder joints! Who ever did this didn’t have an iron hot enough for the job)

That was only the back plate, in the front plate this is what I found:

Stripped wires on the input jacks on both channels.

Broken ground connection on jumper cable to the back plate.

Now, same things but back in their places, repaired!

and that’s all, done!