Bad Power Supply?

I think I may have a bad power supply. I was using my pc like normal, a few browsers open, WMP playing, and I went to click a link, and the pc restarted. It booted and just as it went load windows it restarted. It did that routine twice. Unplugged the PC and its been dead ever since. I didn't smell any burning like I did when my other PC fried one. Pull the cover off of it and didn't see anything out of the norm. Hooked it back up. The mobo stand by led light, lights up but thats all. Sometimes if you unplug it from the mobo and plug it back up all fans will spin, including the PS fan. And thats without pressing the power button.... But will stop as soon as you press the power button. Sound like a bad PS? Just wanting to know because I'm building a new pc anyway this summer so I was just going to buy a new case and PS to start :)

If you have, or can borrow, a multimeter, here's how to test a power supply:

Testing PSU voltages

Or alternatively you can buy a proper PSU tester, they don't cost much:

PSU Tester

ATX12V PSU Tester

Check the power switch (button), too. Remove its connector(s) from the mobo, and with the computer plugged in while off, bridge the switch pins momentarily with a small screwdriver. If the computer boots up, the switch is bad.

I've run into this a few times but it's easy to overlook.

I keep a used power supply around to substitute. You don't have to remove the one from the computer just pull the plugs and plug the other one in.
By doing this you eliminate the possibility of it heating up and cutting out or an intermittent problem.

Quote:

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Originally Posted by jayclark

Sometimes if you unplug it from the mobo and plug it back up all fans will spin, including the PS fan. And thats without pressing the power button.... But will stop as soon as you press the power button.

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Personally I wouldn't be unplugging / plugging power to the Mobo or any other peripehrals (HD, CD, DVD etc) whilst the power supply is plugged into the wall socket. To much risk of being zapped by touching something you shouldn't or short circuit and fry your mobo.

Electrcity is a dangerous thing.

Plus the 5 Volts that are always applied to the mobo unless things are shutoff /disconnected at the power supply tends to burn out connections fast.

I have been designing/building/repairing electronic equipment for over 50 years and damn well know enough to pull a plug. I've also learned that if you have a possible thermo or intermittent problem parts subbing is the best and quickest way to find it. I've subbed power supplies lots times, never hurt a thing including me....

Quote:

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Originally Posted by townpump1

I have been designing/building/repairing electronic equipment for over 50 years and damn well know enough to pull a plug. I've also learned that if you have a possible thermo or intermittent problem parts subbing is the best and quickest way to find it. I've subbed power supplies lots times, never hurt a thing including me....

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If you look at my post again I was referring to and quoted jayclark.

I was making no inference to your post, your ability to understand electricity or substitute parts.

In fact the only connection I had to your post was that I was the next post after it.