I have a newer e-machine which I suspect the power supply is bad in. It will not power on at all so I suspect a bad power supply.

Would it absolutely, positively be what is wrong with it? That's always the issues I have with hardware. I am always afraid to commit to buy a replacement and that not be the problem. Would I be safe to go ahead and get the replacement.

It's a Bestec ATX-250-12E also if you know of any sites for cheap replacements. Thanks.

The power supply could be good but yet you get no response from it. A bad switch, connection or motherboard problem could be the cause. I have seen power supply testers but don't know off hand where to get one. You could also temporarily connect it to another computer just to see if it does OK on a working computer.

But if you do need one, those Bestec power supplies are all over ebay--both the 250 watt model (the one you have) and the 300 watt. Either would work.

You can test whether an ATX power supply works by just shorting pins 14 & 15 & then switching on - for a guide to pins see 'ere
However just because the PS fan spins doesn't mean it's supplying the correct voltages. Most modern systems use standard ATX connections so you shouldn't have any problem in swapping out one PSU for another as long as it has the same 20pin or 24pin connector.

"I know that I'm mad, I've always been mad"

Find out if Emachine uses a proprietary power supply to motherboard connection before swapping.

Do yourself a favor BACKUP!

Report Offensive Follow Up For Removal

The Bestec power supplies that I've seen have an extra voltage sensor line going to one of the outputs but it's not proprietary. They seem to be standard in the newer emachines, compaqs and HPs. I've connected generic ATX in their place and they've worked fine.

So I should just hook up another power supply to it and if it works then it's definitely a bad PSU?

John is right. but the wires are easier to find by their color. Short the green wire in the 20 pin plug to any black wire in the same plug with the plug unplugged. If the supply is good it should start. Just watch the fan. Jim

If you hook up another generic power supply and the emachine starts up then it's just about got to be a bad Bestec. While the Bestec is not proprietary you'll still need to take precautions as ham30 says. So the one you test it with can't be proprietary either--that is, a power supply that's wired differently to accomodate a specific motherboard.

The last one of those emachines I worked on had a bad motherboard and power supply. When I tested it with another power supply it powered up but nothing posting or beeped. Just warning you it may not be as simple as just replacing the PS.