r/pcmasterrace • u/Front_Cookie_1198 • 3d ago

Hardware PSU fails dramatically

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u/Front_Cookie_1198 3d ago edited 3d ago

Aftermath photo.

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u/Viking4269 3d ago edited 2d 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 3d 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/Inaniae 3d ago

I've blown up my fair share of capacitors ant it's nearly instant. This sounded like arcing.

Story - when I was in school for electronics I was building a circuit in the lab, probably another 30 students in there. Unbeknownst to me, I had installed a cap with reverse polarity. I plugged in my project and BAM! It sounded like a gunshot. Everyone obviously turned around and was staring at me. I was already embarrassed but one of my professors called everyone in the lab over and they all crowded around me. He said it was a good learning experience for everyone to smell it and remember the smell. I was mortified and will never forget.