Question about Jl Audio 250/1 Car Audio Amplifier

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250/1 powers on but no output

I have a 250/1 jl audio amp, i tested it on two different cars and two different subs, the amp is the problem.
the amp powers on and everything is green but the problem is that the sub is not moving at all, is there a way to fix the sub output on these amps?
i disassembled the amp but found no burn marks, i have no idea what the problem is. i tried my friend's 250/1 it works great on my car.
so any suggestions?

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Re: 250/1 powers on but no output

If the amp is not going into protect, the power supply FETs have probably failed. In the corner of the amp near the toriodal transformer, there are 4 FETs against the heatsink. When these fail, the 47 ohm resistors at the base of the transistors often fail. If the resistors are dark, it generally means the FETs have failed. If you disconnect the amp from power and measure the resistance from leg 1 to leg 2 of the power supply FETs, a reading of near 0 ohms indicates the FETs have failed.

Posted on Dec 31, 2007

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