What's wrong with my computer?

March 7, 2005 11:23 PM

It keeps shutting down at random.

Since a few days ago, my computer has randomly started shutting down on me. The shutdowns are extremely random - they don't appear to depend on any one activity and they aren't timed (I can go for a whole day without one and then get two in the span of 15 minutes; I can have the computer shut down on me when, I dunno, editing a textfile, then merrily go on to edit textfiles the whole day without further shutdowns).

They aren't "full" shutdowns, either - the power light in front of the computer doesn't go off, but the keyboard light and mouse light (I have an optical mouse) do. At that point, the power and reset buttons on my computer are unresponsive, and I need to physically pull the plug on it to get it to shut down.

Am I right in thinking it's one of the hardware components going the way of the dodo, and that the reformat-and-reinstall (which I'm overdue for, really, but I'd rather fix the shutdown problem first) that's been recommended to me won't help?

And in that case, is there any way of determining what exactly is dying, or at least having a vague idea, before I open up the computer this weekend and spend a day fiddling with hardware config? Any RAM tests or vidcard tests or soundcard tests or... well you get the idea... that I can run to determine whether the hardware bits are healthy or not?

If it helps - it doesn't make any odd noises; sound and video are fine, not distorted or warped; and it's no slower than it used to be before this started.

Any help would be greatly appreciated.

posted by sailoreagle to Computers & Internet (11 answers total)

Best answer: It sounds like your power supply doesn't have enough juice, and is giving out on you. It could also be a motherboard issue, but I'd take a look at the PSU first. Check this power supply wattage calculator to get a rough idea of if your PSU is hefty enough for your PC.
posted by Jairus at 11:26 PM on March 7, 2005

Best answer: It sounds like it could be a cpu fan failing gradually. When it stops momentarily, the processor could overheat and automatically shut down via the bios. Do you have any fan RPM readouts in your bios?

Other than that, I'm thinking a possibly faulty power supply, which could be easily swapped out and replaced. And, on preview, Jairus beats me to it. This would be the best case scenario. How old is the machine/power supply?
posted by ontic at 11:29 PM on March 7, 2005

Thirded for power supply issue. After that, look at your CPU temps, but the fact you said the power lights to your case drop but the keyboard and mouse stay on could be a sign the 12v rail stopped functioning. To prevent hard disk damage, remove the hard drive and go into your BIOS to make sure the temperature isn't too high. While the case is open check for fan obstructions as well. Wait at least 10 minutes in the BIOS with the computer on to get some idea of your CPU temp.
posted by Dean Keaton at 11:40 PM on March 7, 2005

Since I got my new keyboard at work, I keep nudging the power down and sleep buttons that sit underneath Home and End. It's a long shot, but you could be doing this.
posted by seanyboy at 12:10 AM on March 8, 2005

Response by poster: ontic: the computer's about two years old, the power supply a couple months younger (the power network in my house is flaky at best, and I lacked an UPS at the time, so a power surge killed the power supply).

Come to think of it - while the problem occasionally presented itself before, it's become much worse since last weekend - when the UPS failed for some reason (battery had to be replaced), and two powercuts in a row had their fun shutting my computer down.

Here's to hoping it's the power supply then, as it would indeed be easy enough to replace. How would I know for sure? Just buying a replacement one, putting it in and seeing if it helps?

Dean Keaton: you got it the wrong way round - power lights stay on, keyboard and mouse go off.

seanyboy: luckily my keyboard's old enough not to have those keys. (And if it did, I'd pry them out or otherwise take them out of commission. I hate them.)
posted by sailoreagle at 12:58 AM on March 8, 2005

That's the idea. Of course, it would be much less expensive if you had a friend who had one. Normally, you could take it into a non-chain store and they'll have power-supplies to test it with. But since your symptoms are hard to pin down, you'll need a much longer testing period.

The thing with the UPS is worrisome, though. Have you tried running it without the UPS to see if the problem remains? Now it's starting to sound like either a problem with the UPS itself or Windows.
posted by ontic at 1:21 AM on March 8, 2005

Response by poster: Yep, that was the first thing I tried, and nope, the problem stays. Makes no difference whether the computer's plugged straight into power, or into the UPS.

It could be Windows - as I said, I'm overdue for a format+reinstall, really - but I'd like to see if it's a hardware problem first. (Even if my windows install dies, anyway, all my data's on a secondary hard disk. Learned that lesson quite early.)

I'll have to get a new power supply, then, and see if swapping it fixes the problem. If it doesn't, well, having spare hardware lying around for testing / quick fixes never hurts, so the expense's not really a problem.

We have a bunch of other computers at home, but I doubt my father / mother / brother would appreciate their computer being out of commission due to lack of power supply while I tested mine.
posted by sailoreagle at 2:29 AM on March 8, 2005

before you spend any money, run it with the case open and check all the fans are going round, including any little ones on the motherboard and those hiiden inside the psu.
posted by andrew cooke at 5:22 AM on March 8, 2005

This is easy to check for visually, and I've seen it cause exactly the behaviour you describe.

Also, if your power switch is wired up like most of them, you shouldn't have to pull the plug to force-power-down your machine; just hold the power button in for ten seconds or so.
posted by flabdablet at 5:36 AM on March 8, 2005

Done a virusscan lately? It could be a Sasser worm or some other virus/etc that forces a restart on internet connect? That happened to my parents's computer a few months ago.

Sounds like it's a hardware problem though. Checked for dust?
posted by easyasy3k at 4:53 PM on March 8, 2005

Response by poster: A new power supply and several blissfully shutdown-free days later, I think it's safe to say that it was indeed the power supply.

Now I just need to get over the "if I look the other way for a minute it'll shut down" paranoia. ;)

Thank you all :)
posted by sailoreagle at 8:40 AM on March 11, 2005