Random Shut Downs. Ideas And Theories Please

[Dingadilly]

Hello To Everyone

Herein is my problem, observations and possible causes/conclusions that I may have come to.
I'm looking for other ideas or even reasons why it couldn't be what i think it is.

I have an older MS8188E Matsonic board running 2 internal HDD and an extra DVD writer that i put in ages ago along with an upgraded video card. Running Xp SP2.

Haven't added anything new to the system for quite a while so i'm happy to discount a dodgy installation of new hardware as the cause.

The problem is my computer has recently (over the last 7 days or so) begun shutting down at random.

I get no error messages of any kind thru windows. System appears to boot and operate normally. Up until "It" decides to shut down.

These shut downs can be at any time. there appears to be no similarity in program usage or specific time to link the shut downs to as a cause.

Once the system has shut itself down it cannot be restarted.

Unless :
I remove the plug from the mains and replace it. (seems to reset all BIOS info to factory defaults) then the system will boot up with incorrect CMOS settings. (I've had to reset the time date every single ruddy time!)
Or:
Depress the power button on the front of the tower for 5 seconds (time i'd normally have to hold it in to force the computer to shutdown in the even of the OS hanging)
After the 5 seconds i can release the power button then pressing it again will yield a boot up procedure with correct CMOS Settings (ie unchanged)

It has to be the power supply right?

Its just that from what research i've been able to do on this. Alot of people seem to suggest that power supplies "just die"
"You might get a small bang, Or a wisp of smoke, but other than that no real warning that a PSU is about to die"

Also I did hold some data on my system for someone about 3 weeks back while they did a full clean and reboot. Turns out the files i were holding contained an awful lot of trojans/backdoor and spyware progs from quite a broad range of dodgier p2p applications.

I appreciate it prolly seems fairly obvious that the power supply is the cause, and i would be fully agreeable were it not for the fact that if I try to use the comp to do any kind of work, moving, deleting, sorting or anything really, I can expect a power loss in the near future.

IF I turn it on and manage to launch a task, scandisk, image creation, windows update or anything that takes a while to complete. So far it has always completed. If i don't touch the system it doesn't appear to shut down no matter how long its on for!! (Still testing this one out for accuracy but appears to be the case at the time of writing)

Is there any kind of virus or malware that could cause this kind of behavior as far as shutting down for no apparent reason goes?

Or is it just my PSU on the way out?

Any thoughts much appreciated

Ding

 

[STATus h2O]

Usually when a PSU is dead, the computer won't shut down, but just restart randomly. But it could be a faulty PSU, i'm not eliminating that.
Check your CPU temperatures, make sure your CPU is not reaching a ridiculous temperature causing the computer to shut down. Download a program called "Speed Fan" (www.speedfan.com). It will tell you what the temperature of your CPU is. Depending on the type of processor you have, the temperature will change.
Also, run a memtest86. If you don't know how to do that, just go to Memtest86+ - Advanced Memory Diagnostic Tool, and download the .iso of it. Burn it to a CD, and boot from the CD. It will run a long diagnostic of your memory, if it is bad memory, you will know right away.
If everything I listed above checks out ok, then it is indeed a fault PSU, but the only way to really verify that is to replace the PSU with a spare one, and let the computer run for a few hours.
Try those things out, let me know how it goes.

 

[Dingadilly]

Thanks for taking the time to read me.

Had already run Memtest. (I gotta a big pile of progs on an external that i keep downloading under advice from other peeps
Will be adding speedfan to it shortly i think.

I agree that the PSU would do nothing at all if it were truly "dead"

However i have had somewhat of a development over the last few hours.
Whilst trying to fix this one. I took the idea from the sticky post on this forum about Power supply probs.

I decided to myself that overheating is a possibility albeit not a likley one, even so : case opened and a small desktop flan blasting thru the case.

That must've been 2 hours ago.

No shut downs yet.
Could yet be the processor and i still need to download and run speedfan.

Assuming that tests doesn't show the processor cooking I think it safe to assume its the PSU overheating. (No idea why. Its fan still working, as is the processor fan)

But still that appears to be the culprit at the moment. will post back when i get a definate cause and solution to this one

Ding