Resurrected amp, RCM3

[Lavawood]

I was watching a movie and when it was over, it quit. It’s not the fuses, cord, outlet or power tubes. Upon closer inspection, this potted doodad bolted to the chassis, connected to the input transformer looks cooked.
Any ideas?

 

[DVDdoug]

That's a bridge rectifier (4 diodes). You can check it with an Ommeter (DMM/multimeter) or with a DC continuity tester. It's possible that more than one thing is blown... It's pretty common for one thing to blow and take something else with it... If there are any transistors or MOSFETs in the power supply they could be burned-out.

 

[Lavawood]

And over to the $2000 integrated thread I go.

 

[Lavawood]

It was the bridge rectifier, $20 bucks, back in business. Same part for replacement, ID on different side. How does a part like this fail before the power tubes?