Computer restarting problem

December 9, 2007 6:52 PM

My computer seems to be restarting when there's a lot of activity going on - i.e. heavy downloading, many apps, etc. Please help!

Hi,
My computer seems to be restarting when there's a lot of activity going on - i.e. heavy downloading, many apps, etc.

My first thought was overheating, but I installed Motherboard Monitor, and the CPU temperature is pretty stable at 43-44 Celsius (the CPU is Athlon XP 1700), and it doesn't go up right before restarting.

My next guess was power supply couldn't handle the load - we moved recently, and I connected some new things to this computer, such as printer. But the power supply is 480 W, so in theory it should be able to handle it. Is there a way to see if it's at fault here?

I have very little RAM on this machine (384 MB), but I don't think that could ever cause it to restart?

I'm all out of guesses here... any help would be greatly appreciated.

System specs:

MSI 6330 Motherboard
Athlon XP 1700+ CPU
384 MB of SDRAM PC 133
Windows XP SP2
WD 205AA Hard drive - 20 GB

Peripherals: CD-R, DVD-R, Printer (Samsung ML 2010), Wireless mouse/keyboard, DLink USB hub, DLink wireless network card, iphone.

posted by zavulon to computers & internet (13 comments total)

I had this problem. Turned out to be a bad motherboard.
posted by 0xFCAF at 7:00 PM on December 9, 2007

Windows XP reboots when you would have gotten a "blue screen of death" in older versions of windows.

That is, when the OS crashes instead of getting a screen telling you that the system has crashed, XP simply reboots. A lot of programs running together on an older system (which yours appears to be) could certainly cause the OS to crash. Try using different programs than you are using now. If the crash is the result of sloppy code in one program you should eventually be able to figure out who the culprit is. And you could just make an effort to run fewer concurrent programs.

If it's a hardware problem the old method of removing a component to see if the problem goes away is a good way to go.
posted by oddman at 7:24 PM on December 9, 2007

That machine is near the peak of the capacitor plague era, so bad motherboard is a serious possibility. Note that you can repair the system with an upgrade without a new Windows license. You will have to phone Microsoft for activation, but just tell them that the motherboard failed, and that this is a repair.

If the motherboard shows no signs of bad caps, it still may be the problem, or it could be overheating or bad memory.. I would download the ultimate boot CD and run memtest for a couple of complete passes, and then run some CPU burn in utilities for several hours each, and see if you get any crashes. The results should be informative.
posted by Chuckles at 8:18 PM on December 9, 2007

You should look at your administrative log and see if there is any info the OS is giving about the reason it is rebooting.

Start | Control Panel | Administrative Tools | Event Viewer | System |

And look at the events around when the computer restarted - that could give you a clue.
posted by bigmusic at 8:18 PM on December 9, 2007 [1 favorite]

Bad caps are very likely on an MSI 6330, and adding a printer couldn't possibly effect the computer's power supply (well.. anything is possible..).
posted by Chuckles at 8:21 PM on December 9, 2007

Another vote for bad caps. I had the same issue at around the same temperature on a different motherboard.
posted by Kickstart70 at 9:14 PM on December 9, 2007

Sounds like bad RAM to me. The reason I say this is that you mention it only happening under high load, which means high memory usage/swapping. If the bad memory sector is in the upper range that doesn't get paged out that often, then it explains why.

The bad cap situation would be more random I'd imagine (depending on where the cap was and what purpose it served). I suppose if the cap was used for DRAM refreshes, it's a possibility.

You can isolate the problem with memtest86+. Download it, burn it to a CD, and boot off of the CD. It will take a while (with your specs, my guess is at least 10-12 hours).
posted by spiderskull at 11:37 PM on December 9, 2007

I second the RAM. But I'd use the Windows Memory Diagnostic. I don't think it will take you 10-12 hours, though.
posted by Soup at 11:55 PM on December 9, 2007

Memtest won't take anywhere near that long, more like ~1 hour. Sure, it is slow memory, but it is also a very small amount of memory..

As I said though, you really want to let it run for several passes, if possible. Errors on memtest show up for various reasons. If certain memory addresses consistently show errors, it is bad memory, but any other pattern of error and the explanation is more complicated.
posted by Chuckles at 12:45 AM on December 10, 2007

Another vote for bad capacitators. I had a whole batch of those in our company once, all machines started to act up and crash spontaneously. Opening them always led to the same result: bulging and half-exploded caps everywhere.
posted by Nightwind at 1:16 AM on December 10, 2007

Windows XP reboots when you would have gotten a "blue screen of death" in older versions of windows.

posted by oddman at 10:24 PM on December 9 [+] [!]

That's only by default, but can be disabled. Right click on "My Computer," go to Properties/Advanced/Startup and Recovery and uncheck "Automatically Restart."

May or may not help in this case, but the blue screen might yield something useful.
posted by Ziggy Zaga at 3:42 AM on December 10, 2007

The caps that go bad are always high-capacity, low equivalent-series-resistance types, and their function on the motherboard is as reservoir (smoothing) capacitors in the onboard DC to DC converters that supply power to the processor and the RAM. If you operate under heavy CPU loads, you draw more current from these converters and having good ripple filters becomes more critical.

When the caps go bad, the CPU and RAM see much more noise on their power supplies. The noisier the power supply, the more likely it is that a 1 on signal lines will be mistaken for a 0 or vice versa. Since continued operation of a consumer-grade computer is totally reliant on perfect signal integrity between CPU and RAM, it's not really surprising that bad caps often cause random crashes and freezes.

Replacing a set of dodgy caps is not for the faint-hearted. I've done it several times, using only the dodgiest of dodgy old soldering irons, but it's painstaking work and the chances of permanent damage to the motherboard are fairly high. Getting a professional to do it for you will almost always cost more thn a new mobo, but may not cost more than the new CPU and new RAM you'd also need if you can't get a replacement mobo of similar age.

If you're going to do it yourself, you need good low-ESR replacement caps. El cheapo Radio Shack parts with similar capacitance and voltage ratings will not work. The Rubycon ZL series, available from Farnell, is the gold standard. In fact the Rubycon parts have such exceptionally low impedance at 100kHz that it's OK to substitute 1500μF 10V Rubycon parts for 2200μF 10V generics if you need to for physical space reasons.
posted by flabdablet at 11:14 PM on December 10, 2007

If you operate under heavy CPU loads, you draw more current from these converters and having good ripple filters becomes more critical.
Ah, good point. I was wondering where the connection was.

Memtest won't take anywhere near that long, more like ~1 hour.
I just realized that the last time I ran memtest was quite a long time ago, on a very slow computer apparently. So, once again, I'm full of hot air! Listen to flabdablet.
posted by spiderskull at 2:06 AM on December 11, 2007