Repair JL e6450 Amp

[krazchikin]

I can't seem to get my amp working. When all the wires are connected, the green power light kind of dims in and out, so I'm guessing it's not getting a constant power source. Also, the red protected light next to the power light is on, but I don't really know what that means. I have tried plugging up another amp to the system and it powers the amp fine, but can't get my subwoofer working either.....not sure what's going on, but I figure I'd start with making sure the amp is working properly first. Any help would be much appreciated! thanks! By the way, I'm a big noob when it comes to electronics, so try to dumb down your answers for me!

[Perry Babin]

If the amp is in protect mode, it probably has shorted output transistors. To eliminate other possible problems, do the following.

Disconnect all speaker wires from the 'amplifier's speaker terminals' and disconnect RCA/signal cables from the amp. If it powers up normally, the speakers/wiring need to be checked. If it still shuts down (goes into protect mode), the amp almost certainly has shorted output transistors and will need to be repaired.

Are you saying that the subwoofer won't play on the other amplifier?

[krazchikin]

Yessir, I couldnt get the subwoofer to power up, but maybe I messed up somewhere with the RCA converter box. How do I replace the transistors? Can I do that myself or do I need to bring it into a shop? Honestly, I dont think I can spare the 180.00 they're asking for =/ Thanks Perry!

[Perry Babin]

Is the sub a powered sub?

For the JL amp, you need to disconnect it from power and check the output transistors. They're the transistors clamped to the heatsink adjacent to the large white ceramic resistors. Don't let the meter probes make contact with the clamp for the transistors. That could make the transistors appear to be shorted.

When checking transistors (bipolar or FET) with your meter set to ohms, you should not read anything near 0 ohms when the probes are touched to the terminals of any individual transistor in any configuration. If any are shorted (~0 ohms between any 2 legs of any individual transistor), they will likely be shorted from leg 2 to leg 3 but you should check 1-2, 1-3 and 2-3.

Check all of the transistors adjacent to the white resistors. There are 12 of them.