PC Spontaneously rebooting

[Zymz]

My PC has been spontaneously rebooting over the past few days. I've been running a hardware monitor to check temperatures, memory, and voltages, and everything is normal except the +12 V reading, which has been reading upwards of +13.1 V and higher. Could this be the problem, and if so, how can I fix it?

Also, my USB controller hasn't been working and the drivers that came w/ the board won't reload. Could it be related to the voltage problem?

I'd appreciate any thoughts.....

My System Specs:

AMD XP2000 Processor (no overclocking)
Asus A7V8X motherboard, VIA KT400 chipset
->onboard gigabit LAN, USB 2.0, sound (Avance AC'97)
512 Mb Samsung PC3200 memory (1 stick)
40 Gb, 7200 rpm IBM EIDE HD
48x24x48x (16x) Memorex DVD-ROM/CD-RW
Radeon 9600 SE 128 Mb video (no forced cooling)
Windows XP Professional

[Catweazle]

Have you used up to date antivirus tools and syware/malware detection tools to ensure your system is clean? Have you tried a refesh install of Windows to fix up any system file corruption, or even better a format and fresh install of windows so you can be sure it's not your Operating System and software which is causing the problem?

Most problems are sotware related, and are usually the result of system use. Most people blame hardware first up, but hardware is seldom the cause of problems.

Some viruses cause this behaviour, and device driver problems can cause it as well.

[rcrevolution]

I used to have the same problem untill I found out it was my ram that didnt support each other.

[Zymz]

Have you used up to date antivirus tools and syware/malware detection tools to ensure your system is clean? Have you tried a refesh install of Windows to fix up any system file corruption, or even better a format and fresh install of windows so you can be sure it's not your Operating System and software which is causing the problem? Most problems are sotware related, and are usually the result of system use. Most people blame hardware first up, but hardware is seldom the cause of problems. Some viruses cause this behaviour, and device driver problems can cause it as well.

I regularly check for spyware and have Norton running in the background, as well as regularly updating Windows (although I intententionally stay 2-3 months behind the Windows releases). I'm actually pretty good about maintaing my computer and keeping the software free of bugs/viruses.

As for your recommendation to reinstall Windows or formatting, I haven't been able to do either without my PC rebooting or shutting down completely.

One other thing I forgot to mention, I built this PC by hand about 2 years ago, with everything but the video card and CD drive being original.

[Catweazle]

Zymz, if you can't even boot from CD and install Windows again, then it's DEFINITELY a hardware problem, and if it's arisen recently you should look at your system cooling first. Ensure that all fans are working and the dust is kept clear of cooling vanes on heatsinks etc.

After those safety-minded things have been attended to, check that power supply. Pull it out, borrow another from a mate and see if your system runs OK with a different power unit in it.

[Zymz]

I can tell you its not cooling problems. I have AsusProbe installed and its reading well below threshold temps(that's how I discovered the voltage fluctuations). When the problem first started, that's was one of the first 2 things I looked at, along with my motherboard possibly shorting to the case. I also cleaned all of the dust out and checked the fans, connectors, cables, etc.

Since its the weekend, I'm gonna have to wait before I can start switching around hardware. If it turns out it's not the power supply, is there anything else that it might be? That way, I can just sit down and try different things until it goes away(or end up building a new PC).

I appreciate the help you've given me so far, Catweazle.

[Catweazle]

Try a different RAM module.

Check for BIOS setup settings that might be conflicting with your ATi card. (They are notoriously unstable, and have a dislike for AGP 8x and AGP fast writes ;))

Try a different display card.

Pull out all add-in components which use a 'slot' one by one, clean both the edge connectors and the slot itself (dust and lint can give you hell) and then ensure that they are all firmly seated when refitted.

Disconnect drives to leave only your hard drive and see if it becomes stable. Reconnect them one by one to locate which one causes problems if that proves to be the case.

Don't discount the unwanted intrusion either, despite your careful efforts. The vast majority of 'unwanted restart' problems are caused by infections. You can't eliminate the possibility unless you've formatted and installed fresh and clean.

[TallCool1]

My PC has been spontaneously rebooting over the past few days. I've been running a hardware monitor to check temperatures, memory, and voltages, and everything is normal except the +12 V reading, which has been reading upwards of +13.1 V and higher. Could this be the problem, and if so, how can I fix it?

Yes. There is a signal line from the power supply to the motherboard called PSG (power supply good). If the voltage goes out-of-bounds, the system may well shut down. the upper bound on the 12V line is about 13.5V, so it's entirely possible.

Replacing the power supply is probably your best bet. They are no longer economical to repair.

[Zymz]

Well guys, I ordered a new power supply and it appears to have fixed the problem. Thanx all for you help.