You’re concerned your computer troubles stem from a failing (or outright fried) power supply unit. How can you test the unit to be sure that it’s the source of your hardware headaches?
Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.
SuperUser reader Sam Hoice has some PSU concerns:
My computer powered off the other day on its own, and now when I push the power button, nothing happens. My assumption would naturally be that the power supply is done (possibly well done) but is there any good way to test this before I buy a new one?
How can Sam test things without damaging his current computer or other hardware?
SuperUser contributor Grant writes:
Unplug the power supply from any of the components inside the computer (or just remove it from the computer completely).
USE CAUTION HERE (Though you’d only be shocked with a max of 24 volts)
- Plug the power supply into the wall.
- Find the big 24-ish pin connector that connects to the motherboard.
- Connect the GREEN wire with the adjacent BLACK wire.
- The power supply’s fan should start up. If it doesn’t then it’s dead.
- If the fan starts up, then it could be the motherboard that’s dead. You can use a multimeter to check if there is power output from the power supply.
Adrien offers a solution for readers who may not be comfortable jamming wires into their power supply unit’s MOBO connector:
Most well-stocked geek-stores sell a “power-supply tester” that has all the appropriate connectors to plug each part of your PSU into, with spiffy LEDs indicating status of the various rails, connectors for IDE/SATA/floppy power cables, etc. They run ~$20 US.
With a little careful shopping you can even find a highly-rated PSU tester for a measly $6.
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