Elusive hard short help

[foreverstrung]

I've got a 1979/80 Fender Pro Reverb Uriliner, 70w amp that I've been cleaning up and doing a few upgrades on. Of the many times I fired this up to run voltage checks, the last time I did on V8 pin 3, I slipped and hit 4/5 heater pins. POP!, blew a fuse and fried both 100R resistors at the pilot light. (note: the power tubes were not installed but pre amp tubes were). So I replaced the 100R resistors and fired it up, this time with a variac and it blew a fuse at 10v. So I pulled even the pre amp tubes, disconnected the pilot light from the chassis and the 100R resistors and still, blows a fuse at 10v (or less)

So I check for a a "hard short" with my DMM on all of the tube sockets. Heater wires and B+ nodes and everything appears to check out. I can't find this booger....I know that PT wires are cloth covered and this old could dry out and crack so I actually unsoldered them, straightened them out, checked carefully and then soldered them back into place.

I know something like this has happened before. Blowing a fuse at 10v with all of the tubes removed is a tale tell. I'm just not picking up on where.

I'd appreciate any thoughts on where to look to find and verify this short.

Thx

Dave

[JMPGuitars]

Do you have a dim bulb tester? If not, make one.

It sounds like you need to test your PT.