Psu works in one comp but not the other

[aricstaric]

I have an emachines slimline el 1532-01e that went dead after a power surge one day. I pulled out the psu from my personal computer and hooked it up to the emachines and it started up fine. Logically that tells me the emachines psu is bad, so i ordered a new one from Revonate(who we bought the pc from). When it got here I plugged everything in but still nothing. I thought maybe i received a bad psu, however when i take the new slimline psu and plug it into my machine it works with no problem?? Anyone have any idea of what it might be?

 

[evilavatar]

aric,

The surge may have fried more than your psu or the psu you were sent may be under powered. I would start by stripping down your slimline of anything it doesn't need and test one piece at a time. My guess is that your mobo is also shot, but it could be something simple like the ram is cooked. Check out JSC's breadboarding thread http://www.tomshardware.com/forum/262730-31-breadboarding as this might be the way to go.

 

[jasonw223]

Well the first major problem that you have here is that you purchased an eMachines PC...

Try plugging in only the motherboard 20+4 pin and 4pin power and booting your eMachines PC (with the replacement PSU).

 

[aricstaric]

Yeah I agree emachines are garbage however my boss bought the pc before i was employed here. And i did try with just the mobo, and then i tried mobo+peripherals. And evilavatar, wouldnt i not even be able boot if the mobo was shot? And because I have never taken out a mobo before, id really like to try and stay away from it, but I am more than willing since im sure its just a logic thing.

 

[aricstaric]

And i cant say forsure it was a surge either looking back, that was just my guess.

 

[jasonw223]

So why don't you just permanently swap both PSUs?

 

[aricstaric]

Because the emachines is slimline no way in hell i could fit my psu in it ha.

 

[jasonw223]

I'd probably send that slim PSU back then and try another. If your other PSU still works on that system, their replacement should as well. The one you have now may be temperamental for some reason...

 

[westom]

And i cant say forsure it was a surge either looking back, that was just my guess.

To obtain a useful answer means you must first post hard facts. Especially numbers. About one minute of labor with a digital multimeter. Without disconnecting anything. Set the meter to 20 VDC. Black probe attached to the chassis. Touch each colored wire where the wire connects the PSU to the motherboard.

Touch the purple wire. It should measure about 5 volts. But record that number to three digits.

Touch the green and gray wires both before and as the power switch is pressed. Report those numbers.

And finally, monitor any one red, orange, and yellow wire as the power switch is pressed.

Normal is for a defective supply to power a computer. Also normal is for a perfectly good supply to fail in an otherwise perfectly good system. Only way to know (or to get useful answers from others) means buying or borrowing a multimeter. A tools so dumb simple as to be sold even in Kmart.

Either you provide those numbers to have a useful answer. Or just keep replacing parts until something works. Those are your only two options. The former means you also learn how computers work. The latter teaches nothing; may leave you only more confused.