Computer Problem - PC Shutting Down Randomly

[CraigSca]

Once again, going to ask the team as you guys have been there, done that with almost everything.

A little background. My 8 year old daughter's PC - run of the mill system I put together - very low-end. Probably about two years old, 2 GB RAM, AMD64 processor (don't even know what it is), onboard graphics. Small hard-drive and DVD read/write capability.

For two years, we've had no problems with it except during boot-up it can't find the boot drive. However, the second time you boot it up it finds everything fine. Again, this has been ghoing on for two years and we have an easy work-around.

Lately, however, her PC has been shutting down for no apparent reason. This can happen during power-up, while booting Windows, or sometimes a couple hours after boot-up. Things I've done so far:

Booted-up into the CMOS and watched the temp of the CPU and motherboard. Nothing out of the ordinary. In fact, when booted up in the CMOS it never shutdown.

Opened up the PC and cleaned it out. Dust bunnies everywhere, but not caked on the CPU or anything like that.

Replaced the power supply. Bought a brand-new Antec, 380W power supply and the first time it booted up, it shutdown during the loading of Windows.

I'm at my wit's end now. I thought for sure it was either a heat issue or the power supply and I'm finding it's neither. Anyone have any ideas?

Btw, when it shuts down it does so without ANY warning - everything just turns off - the fans, everything. This is not a graceful shutdown in any way.

Thanks for the help!

[RomaGoth]

It sounds like something is missing in the boot sequence. Perhaps an .ini file or something with the master boot record (mbr). If you have the backup/recovery disk, I would recommend reinstalling the original settings. Also, have you downloaded anything? This could be related to some type of virus or malware. I would first just do a recovery to the original settings if possible.

[CraigSca]

Originally Posted by RomaGoth

It sounds like something is missing in the boot sequence. Perhaps an .ini file or something with the master boot record (mbr). If you have the backup/recovery disk, I would recommend reinstalling the original settings. Also, have you downloaded anything? This could be related to some type of virus or malware. I would first just do a recovery to the original settings if possible.

But it sometimes boots up all the way and works fine for a few hours. You walk away and then come back to it to see it has turned itself off.

My daughter hasn't downloaded anything - she's only on Webkinz, Club Penguin, etc., and we have Norton 360 on the box.

Since the last message I tried removing each memory stick and removing the connection to the reset switch on the motherboard. Even with doing each of those things it still abruptly turns off.

[RomaGoth]

Originally Posted by CraigSca

But it sometimes boots up all the way and works fine for a few hours. You walk away and then come back to it to see it has turned itself off.

My daughter hasn't downloaded anything - she's only on Webkinz, Club Penguin, etc., and we have Norton 360 on the box.

Since the last message I tried removing each memory stick and removing the connection to the reset switch on the motherboard. Even with doing each of those things it still abruptly turns off.

Yeah, there is definitely something missing in your system files. I would really consider using a recovery cd and see if that works.

[gstelmack]

Shutting down at random times is not something missing from the boot ini. Shutting down at random times (not rebooting or anything) is probably hardware, although it could be a bad driver.

You already tried RAM. Try reseating the CPU. Try putting a video card in.

Check video drivers. Onboard video in particular is usually cheap hardware / cheap drivers. Check sound drivers.

[weegeebored]

I agree with gstelmack's suggestions. However, what is troublesome for me is that by not going into Windows (leaving it in the bios setup when you were checking temps) it didn't shut down. How long did you leave it in the bios setup? Maybe it would have shut down if left long enough. It's possible that it's malware -- like a rootkit -- but I'm still leaning toward a hardware issue.

Do the reseating first. It might be difficult to reseat the CPU if you have to remove the HSF. You would then need to remove the old thermal grease and put new stuff on. And using a different video card and disabling the on board one is also a good idea if you can do it.

Another thing that you can try is to download a program called Prime95. Overclockers use it to test for stability, but I was thinking that you could run it (if you can get into Windows) to test your box under load. If your computer shuts down right away (as it's under a load now) then it's likely a heat problem. Could be a power problem still, but the PS is new so less likely.

[ozias]

Sounds like a hardware problem, and if the putting new thermal grease on the cpu and heatsink doesn't resolve the issue, it could very well be the mother board.

The layers of silicon could very well be getting hot enough at times to separate slightly, and then you lose an electrical connection inside the mobo, and it shuts off. I've had it happen on older boards, and I've had a new PSU randomly die on me, yet would work again when you power up the computer.

[CraigSca]

But, if it was the CPU getting too hot wouldn't it show when I was booted up into the CMOS? As I said, the temp never gets too high when I'm just sitting there in CMOS (it's actively shown on the screen).

I attempted to re-install Windows thinking it may be some kind of driver issue and it failed about 20 mins in - again, PC just turned off. Argh.

[ozias]

Not always, as when the system is just sitting in the CMOS, it's not actively doing anything, so the computer system would only get so hot to begin with. Once your into windows, the cpu will get used a lot more, as seen by Task Manager. (ctrl+alt+del)

If you haven't put new thermal grease on there, you should try that, and if that doesn't bring the temps down, then you know it's not cpu/heatsink related, but still more than likely hardware, ie. the motherboard.

The mobo's are generally designed to last 5-8 years, granted some last a lot longer, some a lot shorter. Once it starts to get to hot, it dies, and then will continue to do so, as the part that overheated has already gone past what it was designed for, and slowly it will take less heat for that part to fail again. Once the system is cooled off, that part will work once again, until temps get to hot for it.

Since you've already reset the sticks of memory, and replaced the PSU, and have now since re-installed Windows, I'd still leaning towards the mobo being no good any more.

[fantom1979]

Originally Posted by ozias

Not always, as when the system is just sitting in the CMOS, it's not actively doing anything, so the computer system would only get so hot to begin with. Once your into windows, the cpu will get used a lot more, as seen by Task Manager. (ctrl+alt+del)

If you haven't put new thermal grease on there, you should try that, and if that doesn't bring the temps down, then you know it's not cpu/heatsink related, but still more than likely hardware, ie. the motherboard.

This would be my #1 suggestion. This sounds like a heat issue to me, and I don't think your CMOS is getting the CPU hot enough to shut it down. I had a computer a couple of years ago that did the same thing. Fixing up the thermal grease fixed it right up. Also, make sure that there is no thermal grease on the MB or on the connectors for the CPU. I accidentally smeared a tiny amount of grease on the CPU connector and it caused all kinds of trouble. I didn't even know it was there until I grabbed a clean rag and wiped it down.

[MizzouRah]

After reading everything you have tried, my guess is the system board.

[Tasan]

It actually sounds like a capacitor going out on the motherboard. I had this exact issue on a board. A close inspection of the old board showed that several capacitors were swollen. Once this happens, you just need to get a new board.

It could also be a short across the board. Check for loose screws or maybe something else bridging a circuit.

[Khorium]

Are you using a valid copy of Windows?

Pirated and/or expired beta copies have been known to do this.

[CraigSca]

Yeah, it's a valid copy.

I need to run out somewhere and get some more grease and try that. I hate having to go the motherboard route, but I guess it shouldn't be too horrible.

[DaddyTorgo]

mobo's aren't horrible. just make sure it's compatible with the processor. or buy a cheapie combo-pack of the both. doesn't sound like you need a ton of horsepower on that machine.

more of a pain in the ass than anything else