Okay. This is going to be a little long, so bear with me.

I've had this problem with my PC for the past couple of weeks or so now, and it's got to the point where I want to cry. (Okay, over-exaggeration).

A little while ago my computer simply cut out, shutting down with no warning and not coming back on again. Pressing the power switch did nothing. I was slightly concerned, but I guessed the fuse blew, and replaced it. Sure enough, after replacing it, it switched on again, and everything seemed fine.

A few days later, it did the same thing. Switched off with no warning, not coming on again. It was then that warning bells went off in my mind. Surely a fuse can't blow twice within several days? But when I replaced the fuse again, it worked. Or seemed to. Now the problem was recurring. The PC would switch off, and only come on after the fuse being replaced (which, by the way, never blew. I tested it in a different plug and it worked fine, so the second fuse wasn't broken...i.e., it was the computer at fault). I was also later told I would have the same effect if I just unplugged it and left it unplugged for roughly thirty seconds.

I was very worried now. I was told it might dust clogging up fans and causing overheating, so I opened the case and completely de-dusted it. Don't worry, I knew what I was doing, and I didn't damage anything. However, after plugging a couple of wires inside back in (namely the power lead to the motherboard) it wouldn't detect the Hard Drive. I found out the IDE was bust, and it worked fine again after replacing it, but the shutting down problem changed to a rebooting one.

Now all it would do was reboot randomly by itself, again with no warning. However, it wouldn't do it if I installed programs, surfed the Internet or listened to Winamp (a music program). If I tried to play a game like Baldur's Gate however, it would reboot.

Later it worsened to doing it at any time, most commonly during an installation, rarely when doing something else. Games wouldn't run at all. I was told it might the power supply giving up the ghost, so I unplugged the power lead to my writer. It didn't have any effect, but I bought a new power supply anyway, replacing my 550W one with a 600W one. They essentially had the same output though, something which annoyed me. But I figured since the 550W lasted for about a year, the new one should too. No such luck. I've gotten further, like re-installing Baldur's Gate, but I still can't run it. It reboots at the menu, or during startup.

So, after that long-winded explanation, can anyone tell me what's happened, and a possible solution? It may be that I suffered a power surge without breaking the fuse (being 5 amp by the way) and damaging the IDE lead and God knows what else. Or maybe the Hard Drive is dying? I'm considering replacing it, but I want some input before forking out £50 - £70 on a new Hard Drive. I greatly appreciate any help. Here are my stats:

Processor: AMD Athlon 2400XP Running at 2.0GHz
Graphics Card: GeForce FX5200 128MB
On board networking/sound
Maxtor 80GB HDD
DVD Rom Drive
CD-RW Drive
600W, 230V power supply
Asrock K7S8X Series Motherboard

Could I have a virus? Whenever I try and scan using MacAfee or a free online scan it reboots...I haven't tried it recently though.

Again, thank you so much for plowing through this, and I greatly appreciate any input.

[ 11-23-2004, 05:23 PM: Message edited by: slicer15 ]

i once had a similar problem, it turned out in the end that the fan had a blade broken and caused the computer to over heat after a while, but our first huess was that my friend tried to screw with some of the RAM and wasn't properly grounded so the comp shut off because it did not have enough RAM to run on. this turned out to not have caused the problem, but he did screw up the RAM, still havn't gotten around to replacing it. anyway, you can try those two, see if you get anything.

Hm...I guess it could be the RAM too, although I'd have to buy some if I wanted to replace it. That's a new possibility I haven't considered, thanks. [img]smile.gif[/img]

no problem, glad to be of help in a field i have nearly no knowledge in :D

Also check to make sure your fans are running well. This type of thing happend to my sisters comp and i only worked it out by taking the case out and watching it run.

How did you clean out the dust ? using compressed air or another method?

Hope this helps!

I believe the fans are fine. They spin, make no noise and keep the CPU at roughly around 27 degrees Celscius.

I used a hoover for the large areas, and a brush and compressed air for the tighter spots.

I personally believe it's either the HDD, RAM or maybe even software...I'm considering a reinstall of Windows.

Oh, btw, my OS is Windows XP Professional...SP1 I believe.

Thanks for the suggestions!! ^_^

[ 11-23-2004, 07:09 PM: Message edited by: slicer15 ]

First of all, by Hoover, I hope you dont mean vacuum cleaner...NEVER use a vacuum cleaner in a computer, the vacuum created can cause static zaps to occur, and thats not good.
Secondly, the computer im using was having the same problem, whenever I was insalling something it woiuld re-boot, I constantly get "Internal errors" whenevr I run most programs (Winamp, media player, and so on) Thankfully Firefox still works, I have brought it down to two things RAM or HDD, and I unfortunantly believe its my HDD, is it possibl for you to try another HDD withour buying one? That may give you an indication as to what the problem is.

Well, normally I'd say its your RAM, overheating or your power supply. As you've swapped your power supply, and seem to have ruled out overheating, have you tried the likes of Memtest here for your RAM?

http://www.memtest86.com/

I think it's unlikely to be your HD; if it was, it would probably tell you rather visibly because a Maxtor 80GB drive will most likely be self-reporting. Not to mention that unless you use different partitions I wouldn't expect it to be selective in the applications it fails on. You could try a surface scan disk just to make sure, but that'll take a long time.

If you have a large bandwidth connection the Ultimate Boot CD has a ton of startup utils to test for every conceivable problem. (just google for it)

Edit:

As a slight aside, decent power supplies (which I presume yours is at 600W) offer a certain amount of surge protection internally. Providing it's not a crappy cheap unbranded one, it's very unlikely that a power surge damaged your hard drive cables, especially if the surge wasn't large enough to blow the fuse...

[ 11-23-2004, 10:17 PM: Message edited by: shamrock_uk ]

Wow, thanks a lot! [img]smile.gif[/img]

Well, I tried MemTest via the bootable floppy, but it froze and completely locked up at 69% overall, 7% during Test 7. Does that mean the RAM is likely damaged or not working properly? It never completed the scan, and didn't detect any errors up til then, so I'm not sure...

Also, what do you mean when a Maxtor HDD is self-reporting? Does it mean it warns you if the Hard Drive is dying? To be honest, I didn't consider it to be the Hard Drive until now, when I've seemingly tried everything else. It doesn't make any clicking noises at all when it reboots, and doesn't make other sounds either. Just the usual loading grinding sound.

Also, it might be worth mentioning that I do use partitions. Would that make any difference?

Thank you very much for the help!

You could run a stress test using a program called Prime95. This is used mainly for overclocking to check for corrupt ram so you can determine how far to push it, but it should work for your case too.

Also, power supplys aren't always about the ouput of watts. Cheap 400-600W power supplies can still suck, I know that your PSU isn't your problem since you have a new one, but did you get your PSU from a respectable brand at a respectable price (yes, that means quite expensive)?