Computer Randomly shutting down

[Intelman07]

Ok, one of my PCs randomly shuts down, well, at least the screen just goes black. It will do this while booting up, in windows, or in the bios, it really doesn't matter.

I suspected ram for a bit because memtest failed, though even after changing out ram the computer exibits the same behavior. Voltages also appear to be fine. Anyways does anyone have any idea what part is causing this, I am asking because I do not have many if any parts to change out to diagnose this problem, and I do not want to RMA something that wont solve the problem.

Core 2 Duo E6400
Asus P5B-E
2GB Gskill F2-4200-PHU2-2GBLA
MSI ATI x1900XT 256MB
Seagate 7200.10 320GB
FSP Group (Fortron Source) AX500-A, 500W

 

[nullpointerus]

Originally posted by: Intelman07
Ok, one of my PCs randomly shuts down, well, at least the screen just goes black. It will do this while booting up, in windows, or in the bios, it really doesn't matter.

I'd say it's caused by faulty hardware or BIOS settings.

Does the rebooting happen on cold boots, warm boots, or both?

I suspected ram for a bit because memtest failed, though even after changing out ram the computer exibits the same behavior.

So memtest shows no errors with the new RAM?

Voltages also appear to be fine. Anyways does anyone have any idea what part is causing this, I am asking because I do not have many if any parts to change out to diagnose this problem, and I do not want to RMA something that wont solve the problem.

Core 2 Duo E6400
Asus P5B-E
2GB Gskill F2-4200-PHU2-2GBLA
MSI ATI x1900XT 256MB
Seagate 7200.10 320GB
FSP Group (Fortron Source) AX500-A, 500W

GPU: Run something that will stress the daylights out of the GPU. ATiTool's artifact tester and RTHDRIBL's display can do this. Keep it running for a while before checking for the black screen problem, artifacts, or a complete lockup. Also make sure you have the GPU power cable(s) connected directly from the power supply w/ no other fans in-between.

PSU: Disconnect all nonessential items from the PSU and motherboard, remove all but one stick of RAM, etc. and then try to duplicate the problem. If the computer becomes stable, reconnect stuff until it the problem reoccurs. Now you know what the faulty hardware component is.

BIOS: There's an option somewhere in the BIOS to reset everything to the defaults. Try this and see if you can duplicate the problem. Make sure your RAM settings are per the manufacturer's specs between restoring detault settings and saving those settings.

CPU: Lower the CPU multiplier or bus speed quite a bit and retest.

RAM: Lower the bus speed, RAM divider, and/or timings and then retest. Also make sure new RAM voltage is correct; 0.1V higher than spec on my RAM, for example, gave me random reboots.

 

[Intelman07]

I appreciate your insights.

I cannot run memtest, because the computer stays on for a max of 2 minutes or so now. It was never this bad until today, been trying to diagnose this problem for a little while.

These reboots just happen on all boots, warm, cold. The bios has been set to default, I can't really do ATI tool because it won't stay on that long.

I do have no info though, I think the powersupply might be at fault. I have 3 LED fans, and two of them were lit up, but no spinning. I changed the connect around to the one spinning, and the fans spun, so none are broken. I just found that odd. Thanks for the help!

EDIT: Well I think I've seen sparks inside the case, what would cause that? I've tried with two power supplies, the current one which I think is bad, and and older thermaltake I had laying around. I have a fan controller http://tbn0.google.com/images?q=tbn:G97...erra.ru/catalog/img/items/10042_00.jpg laying at the bottom of the case, and that let off a spark when it moved. So either that was some how electrified or the computer case was. The grounds in my house should work, unless something odd happend, and I believe I connected things correctly as well.

 

[Job]

Did u try taking out all the non-essential hardware and leaving only one stick of ram in suggested above?

 

[Intelman07]

Yes, I did, I had one stick of ram, motherboard powered videocard and that is it. I also tried that combo with HD.

 

[Job]

Try uninstalling ALL the ASUS mobo drivers, then restart - install each one again (try get the latest ones) and restart comp btw installsand make a note of whether or not the boot time slows WAY down. There have been documented problems wth the supplied ASUS drivers eg http://www.thepatri0t.net/2006/10/14/asus-p5b-deluxe-problems-solution/

 

[nullpointerus]

Originally posted by: Intelman07
EDIT: Well I think I've seen sparks inside the case, what would cause that?

The only times I've heard of sparking inside the case, it was because of a bad PSU.

I've tried with two power supplies, the current one which I think is bad, and and older thermaltake I had laying around. I have a fan controller http://tbn0.google.com/images?q=tbn:G97...erra.ru/catalog/img/items/10042_00.jpg laying at the bottom of the case, and that let off a spark when it moved. So either that was some how electrified or the computer case was. The grounds in my house should work, unless something odd happend, and I believe I connected things correctly as well.

A bad PSU can damage other components in the case including motherboard, CPU, RAM, and/or GPU. If a known-good PSU does not allow the computer to power on stably, then you're looking at replacing some other hardware, too.

I would bump this thread until one of the PSU experts responds (or find a thread they're in and PM one of them) and ask what to do. Chances are they'll tell you to swap in components from your other PC(s) to see which ones are bad in this PC, then you know what to replace. I don't want to tell you to do something that will cause further damage.

I really feel badly for you. I lost a CPU (K6-2) and system board this way.