computer help - power supply failure ??

[hyiu]

Hi All:

My desktop computer died on me when I'm not in the room...
It was on when I left the room, and when I'm back a couple hrs later, it was off... 

From the look of it, I didn't smell any burned parts....
I tried to turn it on, but nothing...
like no fan turns (not even the one from power supply...)
no lights.. no nothing...

I want to know... is there a way to check if the power supply is dead ??
(regularly, when I give power to the desktop, I'll need to push the push button to start the machine... (and before that... the power supply fan doesn't turn...)
when a power supply is not connected to a mother board... how can we check if its working ?? is there a way to check that ?? I do have a multimeter...

is there a way to know if it is the power supply ?? or the mother board ??
(sorry... I have no spare power supply to try it on the motherboard...)

should I go buy a power supply from some store... test it, and if its not the power supply, return it ?? (I don't really want to do that if I have a choice...)

Any suggestions are appreciated...

Thanks for your help...

[SirPeale]

If it's an ATX, unplug it from the motherboard and all drives.  Take a paperclip and short pins 14 and any ground together.  Pin 14 is usually a green wire.  If it powers up, you have other issues.

[shardian]

Have you already flipped the switch on the back of the machine and let it sit for a while. When power flickers at work, sometimes my machine will not turn on at all - nothing comes on. Once I killed the switch on the back for a few minutes, everything works fine.

So, make sure you try that before going and buying stuff.

[AtomSmasher]

Power supplies are the most common component to break in a computer, so it wouldn't be surprising if it is broken.  Peale's trick should work, but I generally just test mine by hooking up a power supply from another computer into it and see if that fixes the problem, of course you have to have another fairly recent computer around to do that.

[hyiu]

If it's an ATX, unplug it from the motherboard and all drives.  Take a paperclip and short pins 14 and any ground together.  Pin 14 is usually a green wire.  If it powers up, you have other issues.

I have unplugged all the plugs, and I found pin 14 (and it is green !!).

pin 15, 16, and 17 are all black...

do you know exactly which pin is ground ??

that is better than me guessing which is ground....
sorry if its a dumb question...

just want to be double sure before I short anything electrical.

Thanks, and I'll keep you guys informed...

[NightGod]

In this instance, use the computer case as your ground-just touch the other end of the paper clip to anything bare metal in there.

[boykster]

In this instance, use the computer case as your ground-just touch the other end of the paper clip to anything bare metal in there.

actually, no, it wont' be the same ground, as the psu cable is unplugged.  Use any of the black wires that lead to the harness as ground, it won't matter which one.

[jbox]

 

[NightGod]

In this instance, use the computer case as your ground-just touch the other end of the paper clip to anything bare metal in there.

actually, no, it wont' be the same ground, as the psu cable is unplugged.  Use any of the black wires that lead to the harness as ground, it won't matter which one.

Actually, yes it will-I used this test method on dozens of different machines before I finally broke down and bought a PSU tester and I always grounded it out to the case. As long as the PSU is still attached to the case, the case is grounded to it-alternatively, you could ground it out to the metal shell of the PSU if you have it out of the case.

[boykster]

In this instance, use the computer case as your ground-just touch the other end of the paper clip to anything bare metal in there.

actually, no, it wont' be the same ground, as the psu cable is unplugged.  Use any of the black wires that lead to the harness as ground, it won't matter which one.

Actually, yes it will-I used this test method on dozens of different machines before I finally broke down and bought a PSU tester and I always grounded it out to the case. As long as the PSU is still attached to the case, the case is grounded to it-alternatively, you could ground it out to the metal shell of the PSU if you have it out of the case.

Sure, IF you leave it connected to the motherboard, which I wouldn't do while testing a powersupply.  Also, if he followed Peale's directions

If it's an ATX, unplug it from the motherboard and all drives.  Take a paperclip and short pins 14 and any ground together.  Pin 14 is usually a green wire.  If it powers up, you have other issues.

and is confused which wire is ground, then touching the chassis of the PC isn't going to work.  I'm not splitting hairs purposefully, but if he's having issues troubleshooting a PSU, consistant information is key to solving the problem.

[hyiu]

Hi All:

its FIXED !!!   

THANK YOU for all your help...

I disconnected all the power plugs... and then tried grounded #14 (green) with the power supply case metal.... (carefully...)
nothing happened....

so, I also use that to touch the PC case, and still nothing happened...

so I went buy a new power supply, tested it, and waaa laaa !!!
it worked !!!...

I'm all good !!! (and didn't electricude myself in the process....)
its all good now !!!!

Thanks again for all the pointers !!!

   

[NightGod]

In this instance, use the computer case as your ground-just touch the other end of the paper clip to anything bare metal in there.

actually, no, it wont' be the same ground, as the psu cable is unplugged.  Use any of the black wires that lead to the harness as ground, it won't matter which one.

Actually, yes it will-I used this test method on dozens of different machines before I finally broke down and bought a PSU tester and I always grounded it out to the case. As long as the PSU is still attached to the case, the case is grounded to it-alternatively, you could ground it out to the metal shell of the PSU if you have it out of the case.

Sure, IF you leave it connected to the motherboard, which I wouldn't do while testing a powersupply.  Also, if he followed Peale's directions

If it's an ATX, unplug it from the motherboard and all drives.  Take a paperclip and short pins 14 and any ground together.  Pin 14 is usually a green wire.  If it powers up, you have other issues.

and is confused which wire is ground, then touching the chassis of the PC isn't going to work.  I'm not splitting hairs purposefully, but if he's having issues troubleshooting a PSU, consistant information is key to solving the problem.

Gods no, you never leave it connected to the motherboard, all that is required is that it still be screwed into the case. The metal shell of the PSU (and hence the case itself, since the metal PSU is in contact with the metal case) are ground, as well as the black wires in the 20/4 pin motherboard connector.

If you don't believe me, test it yourself-grab a known good PSU that's inside a computer, pop the connectors off the motherboard and drives and then ground out #14 to the case itself.