Bassworx BA1200.1d distorted output

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I picked up this amp for 30 bucks knowing it wasn't working properly. I powered it from my car battery and it powered up fine so I connected a subwoofer and audio in and no sound. I opened up the amp and noticed a burnt trace on the bottom side of the board. I repaired the trace and tried it again. I'm getting mild bass out of it but also a scratchy distorted sound. I'm lost at this point,any suggestions?
 

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I'm not sure what circuit it was in, it was between the blue 106k250v caps, one of the pins on the driver board and to a resistor that is connected to tl074cn

I tried all the pots and switches through their entire ranges and gave them a wiggle and didnt seem to have any effect on it.

Unfortunately no scope.
 
Hi Perry, I have rail voltage(35v) and I'm getting 27v between Vcc+/- pins on the op-amps. Since my last post I discovered a shorted transistor on the driver board I believe it is a 2SA1797-Q. I've removed it from the board to test it just to make sure it was the trasistor that was shorted. Is it common for these devices to go bad or should I be looking for other bad components that may have caused it to short out?
 
Hi Perry, so I replaced the transistor(2sa1797) and the distorted sound issue has gone which is great but the output from the amp is very low,even with the gain set to max. It may be possible that my head unit connection are to blame. Since the head unit doesn't have subwoofer out, I paralleled the rca's for the rear output on the head unit and used one set of rca's for sub output but that setup worked fine with my kenwood mono amp rated at quarter of the power this amp is rated
 
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