Shure Vocal Master Fuse Popping

[neddyboy]

This may be a bit off the hifi trail, but I've had good luck here with my Hafler DH-200 so I'll give this a shot. I'm trying to get a 35-year-old Shure Vocal Master PA amp going. I'm not very experienced with electronics (especially theory), so assume no knowledge.

The amp came to me broken. I replaced a thermistor in the power supply, a common failure in these VMs. Now the amp pops its fuse when I turn it on. I get a thump, then nothing. The thermistor is supposed to prevent the thump, but mostly I just want some guidance on where to start looking for the fuse problem. I'm assuming it's in the power supply. There are no obvious burned or deformed components showing.

Where should I start? I'm waiting for the schematic to come in the mail from Shure.