Rockford Fosgate T40001 BD Help

[scotts530]

Hello I bought this amp from a guy at the local auction in town for 75 dollars he told me that he put the thing in the shop because it started smoking and stopped working. He then told me the guy at the shop he took it to called him about 2 weeks later saying he replaced the transistors in the amp but it still didn't work. That whole story sounded a little funny to me but I bought it anyways . After getting it home I put a power groung and remote wire on it and connected it to a car battery on startup the power light and protect light came on bright for about 4 or 5 seconds then the protect light went from bright to very dim. after about 5 minutes of being hooked up i started smelling something getting worm it was a resistor I took a close up picture of it

[brandes.cm]

You probably have damage to some of the drive circuits. The "shop" probably only replaced the fets, the ones attached to the heat-sink. My guess is they also only replaced the ones that were shorted and you may have some that are leaky.

You did fine with price, the down side is the shop didn't fix it.

The regulators that flank the resistor get warm too, you may have smelled those.

[EBBCO]

Output fets sound shorted. Usually the common in these, when the light goes dim, it's drawing a lot of current before protecting. Replace the output fets as a whole, meaning all of them! Also output driver transistors and gate resistors. This will get you back to stock running condition. Don't just replace blown fets, if you do it will fail very shortly after.

[scotts530]

If it was the outputs that were bad could I unhook the high voltage wires that connect the power supply board to the output board of the amp and power it up to see if it still goes into protect

[EBBCO]

Protect circuit feeds off high voltage rails common ground, so probably wouldnt work.

[EBBCO]

Leave white wire in place and try taking red and blue off. See if it protects