I'm working on a friends amp, It is a raven rg 100, I think it might be the power transformer that is bad. It has very low voltage on the secondary. it has a 68v (ct) . there is five wires on the secondary two blue and a red then yellow then red.
I checked it plugged in and unplugged and the most ac voltage i got on it was 6.00 volts. I can't find a schematic anywhere.
I normally just work on tube amps so I was wanting to make sure  It was the power transformer. I'll appreciate any help