Owner switched on, blue led came on as normal , but between that and 20
seconds grabbing guitar lead, had blown the mains fuse, no input, usual
load. No problem in previous use, may be a drop in volume , as for the
last month had to use 6 instead of 4 on the volume, but uses different
cabs so cannot be certain of that.
Both IRFP27N60K ohmic low all round. With trade mark ground off 8pin
SMPS supervisor, from combined effort here a few years ago, probably
IR2153 ,if like the other flavors of these amps.
Any view as to what would cause this sort of failure? and pre-emptive
mod around the supervisor circuit?
I don't like the great thick slabs of ceramic insulator pads, should be
used on bathroom splash-backs IMHO , not heat conductors.
The main amps not checked over yet.