PC restarts randomly

[PieIsAwesome]

# Overview of the problem
My brother's PC restarts at what seems to be random. Sometimes in a game, sometimes on the desktop, and even in the middle of post.

# Full description of the problem and symptoms
So a couple of weeks ago the PC began to have this problem, first time was in the middle of playing DoW2 online with him. Computer would just reboot, GPU fan does its usual 100% speed for a a second during boot, however I never heard the hard drives shutting down and restarting. Thought it may have been because of load game put on PC but then the same thing occurred while the PC was idle.

I did a few things (described in a section below), problem went away, then a couple weeks later the problem is back.

PC restarted in middle of game, booted up, then started up game again and PC reboots in game's menu. Then PC restarts while browsing the web, then in middle of posting, then repeatedly over and over again about a second after each restart. Finally the cycle ends after a few times and it starts up normally. Then again browsing the web and the repeated instant restarts happen again. Shutdown comp for a couple of hours. Turn on again, restarts while idle, starts up again and seems to stay on.

Currently running memtest for 30 minutes, wonder if it will restart.

# Did it work normally at one time, or has the problem always existed?
Yes, the comp has worked normally before and has only had this problem recently.
I actually used the motherboard (Gigabyte G31M-ES2L) in my own PC for a while and never had this problem.
CPU, RAM, HDDs, all from brother's old build, never had this problem. Videocard (9600gso) is newest addition, but still had it for several weeks or months without problems.


# Is the problem consistent and repeatable, or entirely random, or semi-random?
Semi-random. First only about 3 instances within 2 days, then nothing for a week or two, then today the problem repeats a bunch of times, and now nothing.


# I already tried these steps:
While running Orthos and Furmark at the same time:
Checked temps, normal.
Checked PSU with multimeter, normal.

Changed power outlets
Unplugged modified fans
Tested outlet with multimeter
Checked for shorts (looked in back of motherboard tray, and number of standoffs=number of screws on board, good)
Memtest86 3 passes, no errors

# My software:

Seems irrelevant since the problem occurs outside of windows.

# My hardware

* Motherboard: Gigabyte G31M-ES2l
* Intel e2200 stock
* PNY 9600GSO 768MB
* Crucial DDR2 667 1.8v
* FSP Bluestorm II 400 watt with combined 29a on 12v rails

# Other information that might be relevant

 

[greenbean]

Questions:
What does the PC do RIGHT before the reboot; i.e. do programs act weird and unresponsive? Or just like Emeril Lagasse?

The most unique problem seems to be the repeating reboot, this is indicative of some kind of a short or serious misconfiguration, so i'll concentrate on this.

Things to check:

1. Power related:
a. You may have a power problem on the circuit you're on; i.e. bad power socket, bad power cable, bad power spike or surge suppressor, bad UPS, or bad circuit breaker. (check the socket, cable, and spike/suppressor and replace if they look circa 1985 or older, but skip the rest for now.)
b. Checking a PSU with a multimeter is only half worthwhile; proper voltages can be present, however, the PSU may not be able to maintain them under heavy load. (Hard to check without proper equipment, so skip this for now.)

2. Motherboard related:
a. CPU, Chipset, or RAM overclocked/overheating/oversomething. Reset all voltages and frequencies for these components in the BIOS to default values.
b. Blown or damaged condensor/capacitor on your mainboard. Get a flash light and do an inspection of the board looking closely for caps with bulging or popped tops (Possibly oozing.)

3. Other
a. Inspect all cable connections inside and outside the PC for improper seating or damage; re-seat and replace as necessary
b. Inspect external cable insulation/shielding for damage; i.e. your cute little kitten likes to chew on things.

 

[thegisguy]

Like Greenbean said, Look at the power. I had a very similar issue years ago, before I knew too much about computers. It drove me so crazy I eventually paid a computer repair shop to test each part. Everything tested fine, got it home, Bam rebooted. Mad as a hornet I went back to the repair shop. The guy looked at me, and said "Do you have it plugged into the same wall outlet?". Ran it off a new outlet, and life was good.

 

[Atheus]

Originally posted by: PieIsAwesome
PC restarted in middle of game, booted up, then started up game again and PC reboots in game's menu.

...

I never heard the hard drives shutting down and restarting

...

repeatedly over and over again about a second after each restart.

Right so it sounds like it's not really rebooting but going into some kind of suspend/sleep mode and then sometimes failing to come back. Can you turn this feature off in the BIOS? You haven't been hitting some kind of sleep shortcut on the keyboard have you?

 

[PieIsAwesome]

Originally posted by: greenbean
Questions:
What does the PC do RIGHT before the reboot; i.e. do programs act weird and unresponsive? Or just like Emeril Lagasse?

The most unique problem seems to be the repeating reboot, this is indicative of some kind of a short or serious misconfiguration, so i'll concentrate on this.

Things to check:

1. Power related:
a. You may have a power problem on the circuit you're on; i.e. bad power socket, bad power cable, bad power spike or surge suppressor, bad UPS, or bad circuit breaker. (check the socket, cable, and spike/suppressor and replace if they look circa 1985 or older, but skip the rest for now.)
b. Checking a PSU with a multimeter is only half worthwhile; proper voltages can be present, however, the PSU may not be able to maintain them under heavy load. (Hard to check without proper equipment, so skip this for now.)

2. Motherboard related:
a. CPU, Chipset, or RAM overclocked/overheating/oversomething. Reset all voltages and frequencies for these components in the BIOS to default values.
b. Blown or damaged condensor/capacitor on your mainboard. Get a flash light and do an inspection of the board looking closely for caps with bulging or popped tops (Possibly oozing.)

3. Other
a. Inspect all cable connections inside and outside the PC for improper seating or damage; re-seat and replace as necessary
b. Inspect external cable insulation/shielding for damage; i.e. your cute little kitten likes to chew on things.

It just restarts instantly, no freezing or unresponsiveness or anything.

All voltages and frequencies are at default settings.
I inspected the board and all connections and seating before, but I'll do it again, and I'll try your other suggestions.

I do agree that this is likely a power or short problem. I don't understand why the comp works fine for extended periods of time, and then one day restart madness, and then back to normal. Something must be changing? Would this rule out a short?

The most annoying thing is that the problem goes away then comes back. Solving this problem would be so much easier if the problem always occurred.

 

[PieIsAwesome]

Originally posted by: thegisguy
Like Greenbean said, Look at the power. I had a very similar issue years ago, before I knew too much about computers. It drove me so crazy I eventually paid a computer repair shop to test each part. Everything tested fine, got it home, Bam rebooted. Mad as a hornet I went back to the repair shop. The guy looked at me, and said "Do you have it plugged into the same wall outlet?". Ran it off a new outlet, and life was good.

Yeah, I thought it may have been something like that at first so I switched the outlets and it seemed to have done the trick for a couple of weeks but now its back again. I had him plug it into the same surge suppressor as another comp that has not experienced any problems, but not luck.

 

[PieIsAwesome]

Originally posted by: Atheus

Originally posted by: PieIsAwesome
PC restarted in middle of game, booted up, then started up game again and PC reboots in game's menu.

...

I never heard the hard drives shutting down and restarting

...

repeatedly over and over again about a second after each restart.

Right so it sounds like it's not really rebooting but going into some kind of suspend/sleep mode and then sometimes failing to come back. Can you turn this feature off in the BIOS? You haven't been hitting some kind of sleep shortcut on the keyboard have you?

Hmmm, I'll have to try that.

 

[greenbean]

It just restarts instantly, no freezing or unresponsiveness or anything.

All voltages and frequencies are at default settings. I inspected the board and all connections and seating before, but I'll do it again, and I'll try your other suggestions.

Yea sounds electrical. Two kinds of electrical shorts that can happen in and around your PC:

1. A catastrophic short where something breaks or explodes, which is usually accompanied by smoke, so its always obvious.

2. A random short wherein the environmental conditions present right...NOW, are just perfect, but the short is not strong enough to weld the exposed metal together and once the discharge has occurred (and your PC reset) it waits peacefully until conditions are right again. This one is not obvious and may never be found until you swap out all components one at a time.

Colder weather, humid weather, where you put your feet when you're sitting at the desk, the weight of cellphone charger cable that you just plugged in on surrounding cables on the same power spike...all these things can contribute to case #2. I don't want to distract you from some other problem if I'm wrong, so continue to keep an eye out for other issues, but all the evidence points towards something electrical.

 

[masterbm]

Those can be nasty problems to trouble shoot. Usually had computer that ran in case for 6 months then starting do the same thing. I turned out the board was on occasional touch metal back plate and that was causing. OR the other thing that I have seen happen with other computer sometime people used the wrong screws to secure the motherboard. usually with thee sort problems I will knock the system completely apart and test the system at minimum state(take the system out of the case). The other thing is also have extra power supply around and usually sub that in first to see if that fix it.