Rockford Fosgate 160.2 MOSFETs?

[lukeman269]

Hi, I have a Punch 160.2 and I fried some of the mosfets today. I accidentally had a pair of wires touching together for awhile on the amp while I was running errands. I had a sub hooked up and the box had cheap terminals and I was driving pretty aggressively and the box ended up rolling forward and the wires were touching. I didn't think anything of it as I was driving around, but then when i got home the amp was very hot. I looked under the hood and the fuse popped, so I put another one in and hooked the sub back up and it made a thudding noise and the fuse popped again. So I took it inside and took the bottom cover off to take a look at it and I found that 2 of the mosfets are cooked. Q6 and Q7 is where they are located. I can read the top of each of the burnt out mosfets and all I can see is BUZ 100 on each.

Do you think that if I just replaced those mosfets, that the amp would be fine? Or do you think there is more than meets the eye for this amp?

I'm not really sure about what to look for if I were to find the mosfets, so any help is appreciated.

[Perry Babin]

Have you used a multimeter to check the output transistors on the other side of the amp?

After you remove the power supply FETs from the amp, you need to check the gate resistors (R19 and R20).

[lukeman269]

Originally Posted by Perry Babin

Have you used a multimeter to check the output transistors on the other side of the amp?

After you remove the power supply FETs from the amp, you need to check the gate resistors (R19 and R20).

What should the output transistors read?
What do I look for in the gate resistors?

[Perry Babin]

You need to read the basic amp repair page (link in sig line) and follow the links from that page so you'll understand what you're doing.

For the outputs, you should not read anything near 0 ohms between the legs of any of the individual output transistors. Check them from leg 1 to leg 2, 1-3 and 2-3.

The resistors should read within 5% of their marked value.

[lukeman269]

Originally Posted by Perry Babin

You need to read the basic amp repair page (link in sig line) and follow the links from that page so you'll understand what you're doing.

For the outputs, you should not read anything near 0 ohms between the legs of any of the individual output transistors. Check them from leg 1 to leg 2, 1-3 and 2-3.

The resistors should read within 5% of their marked value.

Hey perry, thanks for the help, I ended up just calling a repair tech locally and he is gonna fix my amp up for me. I just don't have the knowledge to try and fix something like this myself. It sounds like you have been doing this for years, so a lot of the stuff you try to explain to me is like a different language. I am really good at wiring up amps, subs, stereos, making boxes, and any other things involved with installation, but when it comes to the internal workings of amps; I don't understand it at all haha. Thanks again!