Help reparing arc'd socket PCB on Fender Deville

[Gaz]

I've never repaired an arced socket on a PCB before, and I need a little help. My friend's Deville has for some reason arced from pin 2 to pin 3 on the PCB, and it doesn't look so good. The socket itself seem okay, but the PCB is a mess.

What's the best plan of action? I know I will need to clean the PCB to ensure that there's no continuity from the pins, but I don't know what to clean it with or how to proceed from there. I'm concerned the traces are ruined, but I'm not sure how to tell...

Thanks for any assistance.

[R.G.]

Arc damage on PCBs is where the heat of the arc decomposes the epoxy which holds the glass fibers together into volatiles, oxides, and leaves residual carbon, which is conductive. Once an arc starts on a PCB where there is enough current available to feed the arc as a resistor, it will continue to eat the board. The power supply techs where I used to work called it "PCB cancer". Especially in tube circuits, it's conductive enough to throw things off forever.

There's only one cure - cut or abrade every trace of blackened/arc'ed PCB away. If you can do this will steel wool, or fine sandpaper, great. But be sure you cut enough out to get, as they say in the oncology trade "clean margins". If you have to cut away traces, so be it. Traces can be replaced with wire, and epoxied on if need be. In fact, you can repair the board itself with glass cloth and epoxy from a boating store, although that's a real die-hard approach.

[Gtr_tech]

I use a dremel with a drum sander to grind away the charred pcb material.