QSC GX5 fault, anyone dealt with similar?

[BrAdam09]

So I’ve the QSC GX5 that powers up fine, however CH1 shows permanent clip and signal lights (even without a source connected or load connected, and will not produce an output. Now CH2 does produce an output, however clips at little to no input source and distorts heavily.

I’ve acquired a schematic off the interwebs and upon inspection of the pcb, found two resistors within the peak limiter fried, and have since replaced them, but this hasn’t solved either issue.

Beyond that I can’t see any noticeable damaged components, output fuses haven’t blown, so would suspect the transistors are alright?

Thanks all 😊

 

[Enzo]

Resistors never burn themselves, something always causes it. SO wherever those resistors were in the circuit, follow the path to the connected transistors or diodes or other parts that could have failed to cause excess current flow through the resistors.

 

[JonSnell Electronic]

There is probably DC on the output fuses. Fault find the faulty amplifier first.
Ensure the 16volt supplies are correct and the 5volt reference voltage is there.

 

[MAAC0]

I had a similar issue but on two GX7. Replaced the boards since it's all smt stuff.