I don't have a exact schematic for your amp, but I can give you some hints and suggestions...
USUALLY when the output transistors fuse there is a problem at least one level back and sometimes two levels. Often the driver transistors also get fried and sometimes one stage farther where the bias is regulated for the final amp transistors. A schematic is imperative to diagnose and repair unless one replaces every part.
Next, to prevent damage when restarting the amp, put a 100 Watt incandescent lamp in series with the hot power into the unit. This acts as a current limiter and auto-resetting fuse. The lamp will come on and limit the current while one troubleshoots the amp to find what is causing the current drain.
This schematic MIGHT be pretty close to your unit:
I would expect to see Q4 through Q12 destroyed and maybe a few more components. If transistor Q4 opens, goodbye all the transistors! The 1N4004 diodes are PROBABLY big enough to take it, but all the small transistors probably are damaged or degraded... The high value resistors will survive, but the low ohm ones that can draw enough current may be damaged.
Try to analyze what each part of the circuit is for... I think Q13 and Q14 are part of a soft start circuit. This amp is NOT well protected in case of component failure and MANY that fail in the final stages cause catastrophic destruction.
Use my suggestion for the lamp. Often using a Variac to slowly bring up the voltage is handy, but one doesn't only have one available.