JL Audio E4300, lights up, no sound

Ill be tracing audio through the circuit tomorrow, 1khz sine wave here we come!, it uses a front end like Iv never seen before, about 12 tsop-8 IC's (likely double op-amps), and the usual assortment of pull down,coupling,filter bits around them, I did not get time to make out there P/N#, but I bet we will find there double OP-amps, seeing as how I did locate the + and - 15v rails, they were in fantastic condition, I bench loaded them with an external load resistor, no issues at all, full voltage was realized from no load to load, so I think the supply is in good shape.



Ill grab the high res shots in the morning, and post them to amp guts!



Buckle up Perry, this might be 1 more JL bumpy ride!
 
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Do they have a history of going kaput when driven to max gain? the amp came to me with its gain knob maxed out, and IIRC the guys HU was a HV kenwood, in the range of about 8v peak, so the little op-amps got hammered daily till no more. strange they all went at once, he said all 4 channels went down at the same time.


How do you feel about the 5mv idle setting? i was thinking a tad cooler, around 2.5mv?
 
The bias you set is probably not excessive. The average I've seen for amps that had not been serviced is about 4mv. If the amp runs hot at idle, you can set it lower. If you have to reduce it if you have to work on the amp without the sink.

I doubt the op-amps have failed. I was trying to help you understand why they would use so many op-amps.

It's likely a muting problem. Either the muting circuit is defective or the protection circuit is not allowing the amp to release the muting.

Are there any burned resistors?