r/pcmasterrace • u/Front_Cookie_1198 • 1d ago

Hardware PSU fails dramatically

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u/MiniMaelk04 22h ago

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

67

u/Independent-Bug-9352 22h ago edited 22h ago

This PSU turned into a cheap momentary welding machine, and modern inverter welders use capacitors to do the same thing. My guess is 12V rail shorted @ 100-150A, which isn't too far off from welding machine parameters. It's why their circuit breaker didn't trip either, probably still being under 1800W or less from the wall.

They should be turning the IEC cable on from a switch, not plugging it in live from the unit. They should have a circuit-breaker and GFCI inline, and a dim-bulb tester, or at least variac they can slowly dial up.

Also possible this was plugged into a 220V line while the little red switch was set to 110V but I'm not sure if those typically catastrophically fail like this.

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u/Personal_Winter6863 21h ago

Modern PSUs no longer have the little red switch.

They just automatically determine what they are given and run with it.

27

u/Independent-Bug-9352 21h ago

No kidding! I just checked my PSU which is even 8-years-old and you're right, no more switch. Older PSU I have running in another still has it!

11

u/RealityOk9823 20h ago

Was watching a video the other day and the guy was like "I don't trust these PSUs with a 110/220 switch, they're almost always low quality" and I was like "WTF they all have that". Start looking around and, uh, yeah. Well then.

2

u/OkChocolate3501 19h ago

My psus are so old that they never got the switch. I missed an entire gen of nonsense lol.

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u/Personal_Winter6863 21h ago

Haha I also had to run and go check when I learned about this

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u/Alarming-Stomach3902 Linux Mint | Ryzen 7 5800x | 9070 xt | 3060 ti | 32GB 17h ago

They have to be very old at this point, I have a 15+ year old PSU and it doesn’t have it.