Look close at the parts on the other end of the power supply (amplifier
side). Those power device should have two different part numbers. First,
you need to ID the case type. Then find one that is not blown and figure
our if its a PNP, NPN or a Power FET. Then the fun begins about finding a
replacement.
You can usually tell the output devices for the power amps because they
will have low value higher wattage emitter resistors hooked to them.

If you don't have a clue, bail out now.....
Otherwise, post what you find.

BOB



To add to this, if a part is visually blown, it's highly likely that a
number of other parts are also bad, it's impossible to tell without taking
some measurments and it gets expensive very quickly blowing up new parts
because other bad parts were missed.