Do you have the schematic of this amp to refer to?
If the amplifier shows no signs of life, it can mean 2 things.
The positive (or negative) of the power supply does not reach some vital points (or even the remote does not work), OR, which is not unlikely (I have seen many in the past), the microcontroller (pic) is dead, and therefore fails to do any operation (not even turn on the status LEDs).
To avoid any damage to the power supply tracks, check that from the negative power supply there is continuity on the "SOURCE" pins of all the power supply mosfets and on the "SOURCE" of each output mosfet (low side), then check that from the positive power supply there is continuity with the primary windings of both transformers.
Then, these amps are very special, because they use 12v as part of the rail itself.
So, for the latter reason, you should also have continuity between the positive power supply and the anodes (external legs) of at least one of the rectification diodes.
If these conditions are positive, then the problem is to be found in other parts of the circuit, and it is not excluded that the microcontroller is dead.
