I can't find anything close to the circuit in this amp. I'd like to disable the protection circuit but I can't tell you how to easily do that without a diagram. If you post the voltage on the power supply IC, it may be possible to make an educated guess to disable the protection.
If this amp has a normal power supply, pin 10 should cause about the same voltage to appear on the gates of the FETs (if the drive circuit isn't damaged). That should drive 1/2 of the FETs fully on, causing the amp to draw excessive current.
If leg 1 of the PS FETs is near 12v, leg 3 is at ground and the center leg is near B+ voltage, the FETs are blown.