lucas, the prince of darkness has possesed my computer!

July 31, 2006 12:11 PM

My computer has developed a mind of its own and shuts down when it feels like it!

The other day I was playing Civi3 when the computer shut down without warning. At first I though the power went out but the light for the power button was still on. I rebooted the computer without incident and checked the Event Viewer for any possible errors or warnings but everything is kosher (ha!) It happened two more times (once while playing civi3 and when I was doing a print job). Fastforward to this morning, I was running memtest86 and the program was on the 4th pass (no errors up to that point) when the computer shut down.

I usually feel pretty confident about troubleshooting and fixing computer related problems but in this situation I feel at a complete loss as to what I need to know/do to get to the bottom of it. How do I go about troubleshooting this problem? Is there a diagnostic tool I can use to help me get to the source of it?

If it helps, I'm running XP Home on a Chaintech CT-7NIF4 with 768MB of RAM, there are two hard drives but they are not on a RAID.

posted by squeak to Computers & Internet (14 answers total)

I'd suggest opening the case, blowing out any dust, and making sure all connections are tight. (FWIW my PC powers off when I plug in a USB flash drive, but if I ground myself first, it's okay. This doesn't sound like static electricity, though.)
posted by davcoo at 12:24 PM on July 31, 2006

I've had this happen when a short developed on the motherboard. Replacing the board took care of it.
posted by ewagoner at 12:27 PM on July 31, 2006

Yes, it's almost certainly an overheating problem. That's why your computer is failing when you are asking it to do computation-intensive tasks. Dust buildup can contribute to this.

There is a way you can turn on the Blue Screen of Death for these types of hardware failures so that you can get more helpful info; I forget how.
posted by profwhat at 12:28 PM on July 31, 2006

In my experience, these problems are usually related to overheating or a marginal / failing power supply.

First, make sure all the fans are spinning in your case, and none of the vents are blocked up. Download motherboard monitor to see what your temperatures look like. Try running with the case open and a standard fan blowing on it.

If your BIOS has a way to do it, reduce the bus speed or multiplier on the CPU, slowing it down but also reducing the heat and power requirements.

Try taking some of the memory out, one dimm at a time, while re-running the memory tests.

If you can run with one hard drive, go for a while without the second one to reduce power usage.
posted by SpookyFish at 12:34 PM on July 31, 2006

Best answer: I'll add my voice to heat being the source of the problem. My 2nd system has been doing this off and on for about 3 weeks. I've blown out the dust, but something appears to have been wrong with the case fan or the power supply fan.

This morning, I couldn't turn it on. CompUSA's got a super sale on 400W supplies right now (something like 29, IIRC), so I bopped out there, replaced the power supply and the case fan, and it's running just fine.
posted by thanotopsis at 1:16 PM on July 31, 2006

Best answer: And if your power supply is a crappy one, it may be thermal-crowbarring, and not taking all the rails down, which would explain nothing running but the pilot lights.

Remember that the inside of a computer case is commonly 20F above ambient: how hot a room are you running it in? Got a small fan you can aim at the back of the case?

How many fans are *in* the case?
posted by baylink at 1:17 PM on July 31, 2006

I had a similar problem, turned out to be leaky capacitors on the main board. Check out this link and compare your board with the photos.
posted by sunimplodes at 2:42 PM on July 31, 2006

Response by poster: Thanks for the answers thus far.

baylink, I have three fans: 80mm case fan which sucks the air in very well and blows it out the back, CPU fan and the fan on the power supply. I once bought a better case fan to help address the heat issue and when I installed it it roared to life then a nasty burnt plastic smell filled the room, soo now I'm a tad nervous about replacing components ...

I pulled the case apart and gave it a thorough dusting and uh ... when I powered it back up the fans twitched but didn't roar to life, I didn't get a beep, I got nada. So new power supply it is and will be crossing my fingers I don't blow the whole thing up ;)
posted by squeak at 5:14 PM on July 31, 2006

Don't do anything expensive first!!


I had a similar problem and replacing the IDE cables resolved it.

Troubleshooting should always start with the cheapest things first

power cords and cables, drive cables, etc.
posted by Megafly at 5:40 PM on July 31, 2006

But if you *do* buy a replacement PS; spend the money: buy an Antec.

It's not a *real* metric, or anything, but we find they weigh about twice as much as the no name ones.

We've also *never* had a problem with one.
posted by baylink at 7:43 PM on July 31, 2006

My guess is that it's a heat problem too. You can download free programs that will tell you the temperature of your CPU and case.

The best way to get rid of overheating is by opening your case and using one of those cans of compressed air to blow on your case fans, CPU fan, and videocard fan.
posted by atmu at 9:19 PM on July 31, 2006

Try playing a while with the cover off (after cleaning) and see if that helps. If you can reproduce it at will, you're 99% of the way to a solution.
posted by hoborg at 4:39 PM on August 1, 2006

And one final thought for everyone: do not, *in general*, run your PC with the side cover off. Current day PC's are engineered to stay properly cool only if the case is closed and intact; they can and will overheat and fry stuff if you run the for extensive amounts of time with the covers off...
posted by baylink at 7:03 PM on August 2, 2006

Response by poster: 80mm case fan which sucks the air in very well and blows it out the back

Some days I can really sound like a dolt (but I got a really good laugh out of it). I never thought the machine ran that hot, in the summer it gets to be about 25C and in the winter I like it on the cool side, 17C or so.

Thanks for the heads up on the Antec power supplies baylink, mines in the post (as well as new IDE cables) and hopefully that'll fix the problem. Otherwise I think an exorcist is in order ... Can see it now couple of priests looming over my tower chanting, "the power of Dell compels you!"
posted by squeak at 9:39 PM on August 2, 2006