Absolutely quiet now, but putting an amp or so into my battery. It powered up nicely, made a moderately loud buzzing noise (no load), so I unplugged it and connected it to a 12V battery. I bridged the broken wire on the filter, sheilded my face and plugged it in. The other black spot on the circuit board (far left) is under the output resistors, they work fine, but must run a bit hot under prolonged load. Sure enough the line filter next to it had melted a wire clean off, I didn't see it at first because the MOV had left a bunch of residue that hid it. It seems a MOV (metal oxide varistor) is missing (vaporized in fact), but that wouldn't prevent it from working, it just shorts the ac line together when they reach a certain voltage, with it gone it should power up, unless something else is broken. ![]() (Note: I'd already removed the heatsink from the bridge rectifier in the first picture and cleaned to bottom a bit when I took the second picture) It was pretty easy to locate the fault, as there was black stuff all over one spot.
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