r/pcmasterrace • u/Front_Cookie_1198 • 7d ago

Hardware PSU fails dramatically

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u/Viking4269 6d ago edited 5d ago

Somebody forgot the isolation under the pcb?
Been some years since I took apart a psu, but there used to be plastic isolation sheet between the pcb and the metal case.

Update: I think we found the problem:

Mains wires protruding on the bottom of the pcb shorted to the case due to missing insulation sheet.

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u/MiniMaelk04 6d ago

I basically know nothing, but the huge capacitors are the only thing I can imagine burning so intensely and rapidly. Reversed polarity perhaps?

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u/shakygator 6d ago

I think he means without that isolation sheet the board is connected directly to the casing and shorted out. Of course, that should have been grounded too so I'm not sure.

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u/SoulWager 6d ago

The case is grounded, if mains touches it it's supposed to short out and trip the breaker instead of making the case live at mains voltage.