Sorry, i cant help either, but i were in the same boat a few years back.
The amps are made by Indigo in Canada. When mine broke i tried to figure out what was wrong with it. Could net get my hands on a circuit diagram so it was all done by trial end error. An equal amount of both actually so it ended in an error.
I even bought several broken amps to try and figure them out (all had the same fault in the powersupply). I actually soldered and desoldered parts on them so many times that the circuit traces went fubar eventually and i no longer bothered with it. Im not a very good amp repair man though. I just dabble with stuff like that from time to time in my garage
Ended up buying used a 3kw PA rack amp for it and have used that setup ever sinse
All that said i think i read resently somewhere that the rail voltages are variable on theese