Computer Randomly turning off

[karamazov]

I built myself a new computer a little less than a year ago and I am experiencing the following problem:

It will randomly shut off by itself, with no warning. Its a complete power shut down.



AMD CPU
DFI LAN-Party board
Foxconn nVidia 256mb video


I cant for the life of me figure it out. It was on non-stop for three days without a signle problem. Then I shut it down for a night, and the next morning I try to turn it on and it would load windows, let me log on, and then shut down. sometimes it would only stay on for a minute, sometimes it would stay on for 20 minutes.

Ive cleaned all of the dust out of the fan parts/heatsinks for the RAM, video, and cpu. I even took the heatsink off of the the cpu, cleaned the grease off, and re-applyed it.
I set my bios to disable any of the heat warnings/automatic shut down.

I cant for the life of me figure out whats going on.



its been running this exact set-up, error free, no heat problems for a little under a year.


Thanks

 

[auscanzukus]

By shut down, does windows go through the logout process saying it's shutting down or does the pc cut power in a split second?

 

[karamazov]

Its as if somebody went behind my pc and unplugged it. Complete power failure.


This is my third home built pc and this is the first time Ive has this problem and it is quite frustrating as I have online courses for my schooling.

 

[zeroyb]

My guess would probably be the PSU. Do you have another PSU you can try using?

 

[auscanzukus]

2 votes PSU.

 

[karamazov]

I replaced the psu with a brand new straight out of the box one today, and also replaced the cmos battery for kicks and giggles and it still turns off just the same.

 

[Proximon]

Then you have a short somewhere.

Your case button could be bad.
You could have a short on the motherboard, such as a standoff touching the back of the board in a bad spot, or just a damaged/bad board.

If your system was pulling too many amps, your PSU would automatically shut off.

Did you apply too much thermal paste originally? Could some have been squeezed out and making a short (if it's the conductive type)?

I would have guessed PSU as well. Are you buying cheap ones? That's never a good idea, regardless of your power requirements.

 

[karamazov]

I followed the directions to a tee on the arctic silver compound that I used on it. I dont see any squeezing out.

I guess I'll take the motherboard out and try re-seating it all and seeing if that helps. The only reason that I dont think thats the reason is because it will turn on usually for a few minutes and then just POW its off. Ive looked at it from start up to random shut down to see if any fans werent/stopped spinning and the answer is no. Ive even plugged in another case fan to help out the process.


The powersupply cost me about 60 dollars at the local Altec store. Its a logysis brand.

The is the exact one that I have http://www.logisyscomputer.com/viewsku.asp?SKUID=PS550AC&DID=POWERSUPPLY

My exact computer specs are:

DFI Lan-Party UT NF590 SLI-M2R/G Motherboard
Kingston 2gb RAM
AMD Athlon 64 X2 6000+
Foxconn FV-N79SM2D2-OC GeForce 7900GS 256MB PCIE

 

[Proximon]

I see no expert reviews of the Logisys, but expert opinions of the entire line of PSUs are consistently bad.

let us know if re-seating helps.

 

[karamazov]

I took every component out of the case and set it aside (inlcuding the motherboard), dusted everything including the mobo.
i re-set everything individually and let sit for 5 or 10 minutes each.


Nothing individually failed, but everything together I seem to have problems getting the screen to come up. All of the fans are powered on (I can see LEDs or them spinning) but none of the other perhiphrials seem to be getting power. I cant hear the harddrive spinning, and the cd rom doesnt open or close.


This is very frustrating. I am but a lowely fireman. I don't really have money for many new parts.

 

[Proximon]

Did you remember to plug in the 4-pin power near the CPU?

Well, it could still be the PSU... see if you can exchange it for some Antec or OCZ brand.


If that doesn't work then all I can suggest is a new MB.

 

[karamazov]

The 4 pin connector is plugged in.

However, im not sure if the board is 20 or 24 pin

 

[Proximon]

The 4 pin connector is plugged in.

However, im not sure if the board is 20 or 24 pin

You should have a 24 pin main connector and a 4 pin connector near the CPU.