Properly discharging a PSU

Hey everyone. I’ve got a problem with my PSU. The fan is dying. Should be a relatively simple fix. Find fan of the appropriate size, if there’s a typical 3 or 4 pin plug on the PSU board for it awesome, but I’m pretty handy with a soldering iron if there isn’t.

However, I’ve heard experts stress that they’ve properly discharged a PSU prior to working on it, and it got me to wondering what that actually entailed. When I work on the innards of a computer, I kill power to the computer, and then I hit the power button and watch all of the LEDs go dark. Is that proper enough? I’d like to not get zapped when working on the innards of the PSU.

Some capacitors will still hold a charge long after you’ve powered down any electronics, those are the ones you should be careful with not to short.

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That’s all I’ve ever needed to do. It uses up the last bit of juice in the capacitors.


Is the best way and as @KleerKut said, all you really need to do.
Just to be sure, you can use an insulated screw driver to short out any capacitors you suspect of still holding a charge.

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Don’t do this, if you would want to short out caps add a load to the circuit, like a resistor. Simply shorting could damage the cap.
It’s like getting hit to the face, it’s not as bad if the other guy uses boxing gloves.

Capacitors are made to allow for high current flow. Think of the BAE-Systems railgun. It is a dead short!
Not shorting out a potentially shorted capacitor will end in pain, shorting one won´t.

Not so much for high current flow, but rapid charging and discharging. Nevertheless those spkkes are meant to be pushed forward to the circuit, not nakedly back to the cap.
Railguns has coils, those are a load.