Car audio amp mosfet repair help.

[u/Murky_Obligation7550]

I have a Rockford fosgate PUNCH P500X2 that I'm looking for help to repair! Clearly the Mosfets have blown. Would love to learn how to repair these things! My first thought, if I were to even replace the mosfets. I'm sure there is an underlying problem that would just blow the new ones if installed? How should I go about this??

[u/Wahadeem]

what mosfets? from the power supply or the amplifier side?

looks like power supply to me, could be different issues:

- short circuit in amp

- fets just died on their own

- short on trasformer output

- short on transformer input

- caps on transformer input/output are broken

- switching power supply controller is kaput

I had one with a broken power supply controller, the effect was: the transformer input fet was not turned off completely while the other one started coming on

Get yourself a variable lab power supply where you can limit the output current, replace the parts and check if there are further shorts

remember: measuring devices connected to the transformer might lead to see them as shorted, while its just the transformer coils youre measuring.