Comp restarted on its own - need to trace the problem?

That's how I woke up this morning. With a beep. The beep the comp does when it starts up. It restarted somehow. I don't have "automatically restart" checked under the startup section so at most I should've gotten a BSOD or freeze, not a restart.

The OS terminated unexpectedly so I chose "start windows normally", all was fine. I checked the RAM, it has no errors. Nothing relevant was recorded in the system log prior to the restart.

I did a scan with both Symantec AV and the trojan and trend micro online scanners, so I'll rule out any malware from having caused it. I also ran a registry cleanup, but I had run one not long ago so I doubt it's a problem there.

The bottom line is that it's not supposed to restart if it crashes. Also I don't think it was a power surge because I have an UPS.

Can anyone tell me where I should start looking for the cause?

 

Is it occuring regularly? If it is just a one-time thing, then it may be difficult to pinpoint.There could be a number of reasons..assuming its a hardware and not software issue.
-Maybe something overheated? You could monitor the CPU, chipset and videocard temps to see is something is running too hot. Check the fans to see if they are spinning properly?
-Check the power supply unit? I had a nasty FSP unit which used to give intermittent reboots without warning. A bit strange, I know since FSP is a reputed brand, but after I changed the PSU, the problem went away.
-Motherboard problem. Bad caps or something like that?
Can't think of anything else ATM.

 

It was a one-time thing, this morning. I'm leaving it to run over night to see if it does it again, I'll check back here with a reply if it does.

Fans are spinning fine. CPU temp is 50 celsius. I have a HDD fan aswell. My PSU is 450 watt. Also, the "beeping" restart isn't a normal restart. The comp beeps on POST only if it does a RAM check and it only does that when I power on the comp, hit the reset button, or reboot out of BIOS, and not if I issue a restart via software. I installed ChrisTV just the other day, it's a tv tuner program, it has an agent which always runs in the background. It's not Vista-ready so I uninstalled it, suspecting it to be guilty, hopefully that was the cause...

 

It hapened again 3 weeks ago. Twice. The computer suddenly rebooted. As usual temperatures were fine, and a HDD and RAM check revealed no errors. Restart on system crash is still disabled. How can one trace the cause of restarts that happen so rarely?

EDIT: SHOUD I ASK A MOD TO MOVE THIS INTO THE HARDWARE FORUM?

 

I'm not clear about the sequence.

Did the pc restart from cold in the morning or had you left it running/ standby / hibernation overnight?

This is an important question because if it started from cold the restart has nothing to do with Windows.
This sort of behaviour occurs when a 'wakeon' function is invoked in the bios and happens before an operating system is called. Look in the bios for wakeon LAN or wakenon ring or whatever.

 

It restarted while it was running normally, no idle or hiber. It was running overnight. Also, YES I had wake on LAN enabled in BIOS and only disabled it just very recently. Could it have anything to do with my problem?

 

This could also simply be Windows Update installing updates, and some require a reboot. It shows a up popup to Restart now or ignore, and if nobody is there to answer it....it reboots.

Also, stop errors can still reboot the machine, whether it is checked to do so, or not.

If you suspect a stop error, or BSOD, check the sticky on the front page of the software forum.

 

Ahem... WU is disabled from doing so automatically. And as stated before:

1. The POST beep is something that only occurs when a hardware restart is issued.
2. I have experienced one of those restarts first-hand. It was sudden, not like you'd expect from a windows restart to log off and then reboot the comp.
3. Restart on BSOD is disabled.

Studiot I'm still waiting for your reply. You said something very interesting.

 

Um...no. While yes, this very well could be hardware related, that is not a correct statement. I have a machine here that beeps on any kind of reboot.

I already mentioned that you can still reboot from a BSOD, whether disabled or not.

Or maybe you have heat issues?

http://forums.majorgeeks.com/showthread.php?t=136701

I wouldnt trust your readings if a HDD is running at 51c.

I'm trying to help; I don't need any attitude. Deal?

 

When fault finding a good way is to try to divide things into sections working/notworking - similar to a binary search.

The bios can 'overrule' windows and restart under any circumstance so can't be ruled out if it only restarts when windows is running.

As I understand your report, you have not seen it restart from a powered down state. If it did this Windows could be ruled out.

Adrynalyne and Deckard have given a good long list of hardware and software possibilities. Definitely identifying the culprit could take a long priod of patient investigation. Is it really that serious yet?

It will either get better or worse.
If it gets worse then you could try soak testing ovenight running in safe mode, running with the hard drive disconnected, running with a boot floppy or cd instead of the windows hard drive, running with another os installed on the system (including your own windows a second time or the recovery console) each time to see if you can stimulate a fault. Each test would identify an different area of problems.

Meanwhile make sure all the connections are firmly in place.
Random faults on the powerline can also be a cause, as can random signals on connected ehternet/phone/camera/printercleaning cycle.

 

I am seriously at the point of completly overruling any software culprits. If anything BIOS overriding a restart due to wake on LAN could be it. If not, I disregard any posibility of software being the cause.

I am swinging back and forth between SW and HW because I disabled restarting on BSOD - the only thing that could cause such sudden restarts, and at the same time I can't find anything wrong with my hardware... also, power fluctuations on the line are out of the question because I have an UPS. On top of that the rarity of these events make progress in finding out the source slow, because I try to change something after each restart, and have to wait a long time to see if another happens. This is very frustrating.

What you are saying is perfectly logical and keeping the computer on without ever booting into the OS would be a solution to determining wether or not the BIOS or hardware is doing this. The problem is the sheer rarity of these events. My computer would have to run for maybe a month without being useable, and I need it.

Regarding connectors, my PSU is a Thermaltake 470W and has been recently installed, I HAVE checked its connectors thoroughly when installing it precisely to rule out a connection problem causing reboots. But they continued to happen. I'm confident that the PSU is trustworthy.

As for the restarts, I haven't had one in 3 weeks even though I had two at less than 2 hours apart before that. They seem to be occurring quite randomly, and not getting better or worse. All but one have occurred at late night hours, during idle periods. One occurred during gameplay(WoW) and was spontaneous, without any freeze, BSOD or anything, like pressing the reset button on the case.

I suspect my UPS to be to blame since I haven't had these problems before buying it. I bought it 3 months after building the system and had no such problems before that. Then 27 days after installing it my first restart happened. I had it serviced. So far it's running fine without it. But then the guys at the service tell me the UPS came out clean, so I don't know what to think.

-IF- BIOS was indeed rebooting in response to WOL events it won't do it again from now on. I have disabled it. It had been enabled until a few days ago for I don't know how long. I might have actually enabled it myself around the time I bought the UPS and forgotten. It's been so long I don't remember. The computer WAS indeed connected to the Internet at all times when these restarts occurred. Keep your fingers crossed, I'm in for a long wait...

I have a question regarding another common problem on two other potential culprits:

CPU - if I understand well, when the CPU screws up the computer should freeze not reboot right? unless it's too hot. and hot, it isn't.
Bad caps - my MB model doesn't seem to be on the bad caps list, but if it was indeed a bad cap, wouldn't it have gotten worse and worse until the mobo died?

 

There is a rootkit that can cause this: look for 'spooldr.exe'. If you havent got that file your pc isn't infected.

 

Spooldr.exe was not found. Also, I had one complete reinstall of Vista during this period and it's unlikely I could've gotten both infected. I have antivirus installed.