Randall-RG-80-112

[jshag]

Just got this in the shop. Played for less than 3 minutes. CB(Trip & Hold) opened up. Removed power, CB reset. Power up again and GFC tripped. Checked all 4 power transistors, nothing shorted or open, tested diode bridge, measured OK, 2 main power supply caps measured OK.
I need a variac for the bench anyway. Anybody see this before?
JJ

Of course the obvious is the power on switch lever was broken off. I'll start there tomorrow. Any thoughts on leaving it as wired with polarity reversal?

[The Dude]

OK, ...... I'll do it.

http://milas.spb.ru/~kmg/files/schem...e%20Manual.pdf

Edit: Check for leakage from AC to chassis.

[Randall]

Oh boy, does that print ever look familiar...

Lift the .005 cap from the power switch to ground, does it still do it?

[Enzo]

And check bias, how much mains current does this unit draw at idle?