Vintage tube amp resurrection with Variac?

With tube rectifier things get simpler because tube rectifiers reach operational voltage slow enough to catch problem with or even without variac.
With variac set to operational voltage and voltmeters attached to the bias pots or resistors and one attached to the rectifier output you can monitor gradual voltage increase. Once bias on any of the bias pots goes beyond tolerant, you can bring back variac to the noted voltage or below or turn amp off and inspect circuit elements around the fault bias pot or resistor.

Czarivey:

Your advice does nor gell with the tech that worked on my Pilot 232, nor the advice I received from the AA forums.

Basically I was told that a GZ34 will not start to pass current until it reaches 80-90 VAC (which is 4-5 times higher than one wants to start when reforming lytics).

Dekay I mentioned earlier replacing all DC supply caps before even getting onto the variac.

Czarivey:

Also forgot to mention that if using a 5Y3 (in place of a GZ34) it needs to be replaced with the proper tube once you get up to higher voltages (very important point left out).

Sorry, didn't notice the DC cap info.

I once used the light bulb method (think it was on a Pilot 240) and it worked well.

In my environment I have to pay rent and make sure that investment in rent is returned. Mostly I restore items I purchased from estates or items purchased in bulk by pound.
Replacing DC caps takes me less than hour on most tube units.