Hi there,
I have been fixing the phono stage on a Pioneer SX-434 and whilst testing it without a heatsink on (very naively I know..), I have blown the power transistors and a couple of the transistors preceeding them in the signal chain. I have replaced these no problem, expecting the receiver to now work. However:

When I turn the amp on, no matter which input is selected, I just get a 100Hz hum with no audio output whatsoever, level and tone is irrelevant of the master volume or any other pots for that matter. Power supply caps and diodes seem ok. This has me stumped.

Does anyone know if there is anything else that may have blown when the power transistors blew and shorted out?

Thank you for any replies,
Zack