Locked room computer mystery

August 18, 2006 6:06 PM

I was away from home for a week. When I left my desktop was fine. I came back today and it is randomly either freezing or restarting after 5-10 minutes use. I took the side off and no hardware is making funny noises. What could the most likely culprit be? I can't get it to stay on long enough to do any testing.

I took the side off and no hardware is making funny noises.

What could the most likely culprit be? I can't get it to stay on long enough to do any testing from a software side, but when I left nothing was reporting itself as bad.

It's an Athlon 2400, 1 gig DDR RAM in 512 meg sticks, radeon9800 pro, sb audigy, and ASUS A7N8X motherboard, with a 30gb master and a 250gb slave hd on the same IDE channel.

posted by Silentgoldfish to computers & internet (14 comments total)

Sounds like a driver issue. Did you install any software just before you left?
posted by rinkjustice at 6:24 PM on August 18, 2006

Overheating? Check your fans, and download one of those freeware programs that monitors your CPU temp.
posted by chrisamiller at 6:30 PM on August 18, 2006

No software installed that hadn't been on for at least a couple of weeks before I left.

Overheating's a possibility, but the fans seem okay. And I can't seem to get the thing to stay on long enough to download anything on it -- I'm on my laptop to connect to the net right now!
posted by Silentgoldfish at 6:41 PM on August 18, 2006

Take out 1 stick of ram at a time and see if that helps.
posted by Mr. Gunn at 7:01 PM on August 18, 2006

Three things strike me as likely possibilities: some sort of software corruption (bad drivers, virus, or just some bad sectors causing instability), some of your RAM going bad, or your computer is overheating.

My recommendation is to download memtest86+, burn the ISO to a bootable CD, pop it in, and reboot. Let it run for quite a while. Three things will happen, and which it is will tell you what's happening:

If the computer reboots while running Memtest, it's not a software issue, and probably not a RAM issue. Your machine is overheating, or has power supply issues.

If the computer does not reboot, but shows lots of red lines, you have some bad RAM. Shut down and remove one at a time.

If the computer doesn't reboot, and Memtest doesn't complain about bad RAM, then it's a Windows problem. Look at viruses, or driver issues.
posted by fogster at 7:14 PM on August 18, 2006

Since I actually don't know that you're running Windows, "then it's a Windows problem" should really read, "then it's an OS problem."
posted by fogster at 7:16 PM on August 18, 2006

You didn't leave it turned on and connected to the Internet, running Windows, did you? It could well be some sort of network-borne malware. Just a thought.
posted by cyrusdogstar at 8:00 PM on August 18, 2006

Is the computer dusty (on the inside)? Everything could be working just fine (fans run, disks aren't corrupt, etc.) but the accumulted dust can cause your system to overheat. A nice blowing out of the interior compartment and parts with compressed air will clear up the problem. (It worked for me.)

You might just want to blow at it even if you think it's not too dustly. A clean system is a happy system.
posted by oddman at 9:31 PM on August 18, 2006

Or try an Linux Live CD.
posted by sophist at 2:33 AM on August 19, 2006

Check your power supply for loose cords or shorts.

You left your desktop on for a week while you were gone? Shame.
posted by unixrat at 6:52 AM on August 19, 2006

Umm, my desktop is on 24/7. Some people may have reasons for leaving their computer running. No need to tsk tsk.

Sounds like your power supply could be on the fritz. I'd try replacing it.
posted by Roger Dodger at 8:16 AM on August 19, 2006

I have (damn close to) the same system - A7N8X with an XP 2600. The motherboard comes with a check utility (Asusprob). Does it report anything weird - overheat, fan speed issues, or similar? If you're overheating that can cause some issues.

If you're on Win2k/XP/2003, check your task manager (ctrl-alt-delete, or right-click on task bar, choose "task manager" - sorry if you know how to do this but we must always assume you may not, right?). Check the CPU load under "performance". Is it spiking or staying fairly low, as it should under casual use? Check your running processes; check "show from all users" just in case. First sort by name, and visually scan the list to see if you note anything that looks like it should not be there. Then sort by memory usage and see what is using the most. Should that (those) program(s) be running, and if so should they be at that level of use?

If you see anything that just feels off (or even if you don't): three suggestions.

1. You have some corrupted files or drivers. Run a system file check (Start --> Run --> "sfc -scannow"; requires your Windows CD) to scan and repair/replace modified system files. Try reinstalling or updating drivers for your video and the nForce chipset.

2. You may have some sort of relatively innocuous malware. SysInternals "Process Explorer". Get it, run it, tell it to verify code signatures. Double-check any and all unverified MS programs or anything else that looks strange. Try killing processes that should not be there. Good idea to also download SysInternals "Autoruns" (verify signatures, hide verified MS entries) and check - this will tell you what loads on startup, and from where. Again, if it looks off, kill it and see what happens.

3. An alternate possibility - and one that totally sucks - is that you've been nailed by some malicious malware, like an IRC bot backdoor. Happened in my lab to one system - the freezing, etc. was a symptom. Open command prompt, run "netstat -an" and look at the resulting list - if you get a HUGE list of open ports and connections, etc., be very suspicious. These things tend to hide in places like your recycler folder (nearly impossible to see in Windows but can be accessed vis command prompt if you know how) and are a huge pain to remove (manual labor and visual scans of all system files required). Might be less of a pain to nuke the system and rebuild from zero.

In any instance, running anti-malware such as Spybot, Ad-Aware, and the Windows Defender beta are good ideas. Any one of these (even on full scan) will not find everything. All three together may get most of it. Spybot tends to be under the radar of many malware so start with that - other more well-known programs are occasionally detected and shut down before they finish scanning. (If this happens, try to get your hands on a bootable rescue disk such as a BartPE build and scan from there.)

Good luck with it...
posted by caution live frogs at 8:47 AM on August 19, 2006

Tuesday was Windows Update day...
posted by misterbrandt at 10:00 AM on August 19, 2006

Looks like the RAM be it. Thanks.
posted by Silentgoldfish at 1:39 PM on August 19, 2006