Arcam Alpha 3 Int. Amp. what caused this!

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Hi all, I bought this off ebay 'untested'. Looked great untill I took the lid off!
please see photo; before I just replace them, what could have caused these resistors to become charcoal?
 

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Hi,
This damage can only be due to massive overpowering.

It is very likely some other components are damaged as well.
Semi conductors blow first to protect fuses is a humorous way of saying the semiconductors do not tolerate overload very well.
Resistors tolerate overload a lot better than fuses.

I suspect that link has been added to bypass a burnt out trace. That would high current indeed.
 
The mod on R24/R124 is an official factory mod to reduce turn-on thump.

The wire from R127 to R206 does seem like it's a replacement for a damaged +V trace. R206/202/203 provide power to the LED.

I would say there is a lot of damage here. If i had to take a guess, the output transistors and VAS failed, and the VI limiter blew the resistors up. Fortunately, the parts in this amp are very cheap. The most tricky parts are the FST239/240 transistors - these were replaced by ZTX653/753 IIRC.

If you are very keen on repairing this amp I would replace all of the power amp transistors. Rapid stock all of the transistors used.

I've uploaded the service manual here
 
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