Hoffman Pro Junior - PT has fried, trouble shooting tips?

[rickenbackerkid]

Hi all.

5-6 years ago I replaced the PCB in my Pro Junior with a Hoffman turret board.
From my notes, I used a Hammond 290XEX PT and Hammond 1760F OT. The only modification was a negative feedback switch, and a 8/16 ohm switch on the output so I could use either the internal speaker or an old Marshall 412 that I had at the time.

A couple of days ago I turned the amp on and it sounded just like usual for a couple minutes, then abruptly died, with a strong electrical smell. I had a quick poke around and realised the PT was extremely, extremely hot, so I powered the amp off and have not turned it on again. I had first thought that the PT has just shorted internally and I would order another, but I realise that potentially a shorted valve or maybe a cap could be at fault, and if I just install a new PT, I might just melt that too.
Ditto if I try some new valves, I might kill them and they are too expensive to take the risk.

My current plan is to desolder the PT and run it up on the bench to check voltages, which should tell me if the PT has failed. If the voltages check out, what would be my next step? I do have a lightbulb current limiter but don't have a variac to bring the voltage up gently.

There is no swelling in any of the caps or other components and I have not had any issues with the amp, it was always sounded really good and been reliable.

[sluckey]

If PT checks good the next step is to check bridge rectifier, then check for shorted filter caps.

A strong electrical smell could be the PT. Transformers have a different smell from caps, diodes, resistors, etc. If the PT burned you can usually still smell it even if it's been a few days since the issue first occurred. Put your nose very close to where the wires exit the body of the PT.