Rockford Fosgate 301S won't power on

[chipper]

Hey I have a punch 301S the problem is it won't power on nothing. I checked the power supply fets they don't appear to be shorted and the output stage. There's no short in either channels. Can anyone shed some light on this one? Thanks

 

[chipper]

I also get 4.56v on the gate pads of the power supply mosfets. Could it be a rectifier or regulator?

 

[Perry Babin]

Do you read 0v on the center legs of the rectifiers?

 

[chipper]

Yes I do nothing on either leg of the rectifiers. There's also no 12v on the legs of the power supply fets.

 

[chipper]

I think I found the culprit an open trace in the drain of the power supply fet... I'm going to re solder it and see what happens.

 

[Perry Babin]

If that is the problem, you need to scrape the solder mask back and use a small wire to bridge the gap (similar to what's seen below).

 

[chipper]

Will do make it really strong. It was actually they problem to this amp. It fully works plays audio clean. How does that trace open?

 

[Perry Babin]

The trace is relatively small. If the fuse in the B+ line is too large and there is some sort of fault (or the amp is connected to B+ and ground with reverse polarity) the trace will open.