[tdelahanty]

Off or stand-by why would you leave a source active (playing music) and turn on the amp?

I reviewed your repair parts list again. It seems both channels had the p/s caps replaced and one channel had all the output transistors replaced plus the thermal track transistors which monitor temperature and bias and shut-down the amp if too hot. This tells me your amp was over driven to the point of destruction or had it's output shorted.

It seems clear it came to you in this condition and the amp could not have been checked out and certified operational with such a massive failure.