I've seen several S/SX Soundstream amps with damaged boards around blown MPS8099/MPS8599 (Q59/Q56/Q55) which is part of the auto high-current circuit. Now this particular amp will actually power and play but the amp is stuck in high current. Obvious board damage etc. I can cut out and repair this but...
Why does this even happen? Is there a modification I can do to help hold the circuit from failing? I dont see any other issues with this amp at this time.
Why does this even happen? Is there a modification I can do to help hold the circuit from failing? I dont see any other issues with this amp at this time.
It looks like an arc formed after the transistor failed and that burned the board (vs excessive heating during normal operation). Mounting the transistors as high as possible above the board, may help.
Inserting a resistor between the emitter and the board may help. Something like a 1 ohm, 1/8w may work. Typically, very low ohm, low wattage resistors (even non-flammable type) will open without burning. Test to confirm by connecting 12v across a test resistor to see what happens.
If you do this, you need to force the amp to switch multiple times to confirm that the resistor survives the switching.
Inserting a resistor between the emitter and the board may help. Something like a 1 ohm, 1/8w may work. Typically, very low ohm, low wattage resistors (even non-flammable type) will open without burning. Test to confirm by connecting 12v across a test resistor to see what happens.
If you do this, you need to force the amp to switch multiple times to confirm that the resistor survives the switching.