This is a late model 400, in really rough shape. When I originally brought it up on a variac & DBT, it generally worked - FM played, and my phone through the AUX worked ok. The tuning tube did not light up, but that is a problem for another day. So today I replaced all 4 can capacitors, carefully checked my work, & fired it up again. I had sound from one channel only. I switched the speakers, same channel from the amp had no sound on either FM or AUX, just fairly loud hum. While I was poking around, the twin 1000 mfd can cap started to smoke. Long story short, the speaker wires on one channel were shorted together. I am 99% sure that was not the original issue, that the connector pulled partway out while I was tilting the receiver up to look underneath. Does it make sense that shorted speaker wires would cause this (I hope)? So while I am waiting for my replacement caps to come (5 - 7 business days), what else can I check for collateral damage, and what else can I check for my original problem of no sound in one channel (other than my wiring work)?