Rockford Fosgate Power 300

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Hey everyone, new poster here. Trying to fix up an old Rockford Fosgate power 300 amp. I noticed there was no output on the rear channel and then noticed that two of the fuses were blown. I believe the fuse holder circled in green in the attached picture is the -25v fuse from the schematic and the one in blue is the +25v fuse.

Opening it up I noticed that the 100 ohm resistor by the A06 bjt near the IRF542 mosfet had completely blown (circled in purple).

Out of curiosity I probed the output FETs with a DMM and found that they were shorted from drain to source which doesn't seem right (circled in red).

I plan on replacing the blown resistor as well as the two output FETs and seeing if that works.

However I'm not sure what might have caused this to happen (old age?) but it be great to get some feedback on my repair plan as this is my first time doing this and I'm wondering if I'm overlooking something.

Thanks!
 

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The blue fuse holder is for a different channel so that channel may be defective as well.

I'd order the op-amp, several MPSA06s and MPSA56s and several 1N4148 diodes unless you have a local supply house. They may not be defective but they're cheaper than shipping if you find they're defective later.

Order the correct fuses unless you can get them locally. The only ones I can find locally are 10 amps are higher.

Age could be a factor in the failure.
 
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