computer shuts off for no reason...

BPerron

What would cause a computer just to turn off...I have fans going and all are working and I do not think it is getting to hot...I replaced the power supply and it still does it...what else would cause this...any help would be great.

Thanks.

ChrisJ

Hmm... tough one. Does it go off at random times? Can you give more system details?

You could have a faulty power switch. It could also be something like bad memory. Though that would usually cause a hang, and not a power off.

Did you add anything recently to the system (except the new PS)?

I'm assuming this is a Windows system. You can check the logs and see if there are any red events.

Right click My Computer -> Manage -> Event Viewer. Check System and Application.

pyry

It could well be an issue with the motherboard. Do you know how to check it's capacitors for signs of damage? (they're cylinder shaped things about the size of a pinky finger, but shorter, you'd be looking for bowed out tops and leaks)

cmason

Had similar problem, and it was CPU overheating...there is a failsafe that shuts the machine off to keep from killing the CPU. One clue is this happens more often on a hot day that cool one. If you built the PC yourself, the most frequent culprit is bad thermogrease application, or it has dried up. If the CPU fan has failed, can cause this as well. The fix for these is replace the CPU fan, and clean and reapply the thermogrease (very thin application works best).

Infrequently, spyware/malware can do this as well. to check, run either your Windows startup CD or maybe a version of say Ubuntu from a CD, and see if the machine shuts down still. (this elimnates your HD installation from the mix). If it does, it is heat/physical failure. If not, malware could be contributing.

pyry

cmason wrote:

Had similar problem, and it was CPU overheating...there is a failsafe that shuts the machine off to keep from killing the CPU. One clue is this happens more often on a hot day that cool one. If you built the PC yourself, the most frequent culprit is bad thermogrease application, or it has dried up. If the CPU fan has failed, can cause this as well. The fix for these is replace the CPU fan, and clean and reapply the thermogrease (very thin application works best).

A CPU cooler full of dust would do that too, even if the fan was still going.

jww

You might try looking at the system logs for any clues.

Also.. most motherboards have software that will tell you the temps as well as give you warning alarms.

Good luck!!

cmason

jww wrote:

Also.. most motherboards have software that will tell you the temps as well as give you warning alarms.

Good luck!!

Sadly, often this is limited to those made for overclockers and the higher end. I found out the hard way that you indeed get what you pay for. Some boards do support speedfan and tools like that, at least it is worth a shot:

http://www.almico.com/speedfan.php

hgernhardtjr

FWIW, I just solved that very same problem on my photo editing computer.

I pulled an expansion card, one at a time, after replacing the PS as the problem continued and all core temps were just fine. Ultimately, I found that when I subbed in an ancient video card I had on hand, the computer did not shut down. So I replaced the video card and all works fine now. The same thing happened on a friend's computer several months back, and I traced it to an aging and faulty secondary HD controller expansion card.

If you haven't already, you might try substituting cards as I had to and see if the problem goes away with either the removal or substitution of a specific card.

Other than that, such a shut-off problem can be hard to diagnose.

jww

cmason wrote:

Sadly, often this is limited to those made for overclockers and the higher end. I found out the hard way that you indeed get what you pay for. Some boards do support speedfan and tools like that, at least it is worth a shot:

http://www.almico.com/speedfan.php

Oops.. Thanks for catching that!! I meant to say that temp monitoring software "might be available" depending on the MB.

In rereading the OP's issue.. If it doesn't seem really hot.. recheck any loose boards, loose cables.. possibly just reseat everything.

I am wondering if it might be something less obvious. I remember a long time ago, someone had a system that would work like a champ, but every once in awhile it would just die.

I pulled it apart and could make it run flawlessly if the case was off. Found out that the way the hard drive mounted that it's board was actually coming in contact with the metal case causing it to intermittently fail due to vibration.

Remounted the drive insuring clearance and never failed again.

i_worship_the_King

If you think it's a temp problem try this program - it does a great job and has worked on every computer I've tried it on (PC based).

http://www.softpedia.com/get/System/System-Info/Motherboard-Monitor.shtml

Otherwise I would guess (as others have without looking) that it's either a card gone bad (are you sure they all still work? including old network cards or others that are not in use), Bad RAM (this would be my first guess - cheaper RAM can die within' a year), and lastly a software problem.

You can try running CPU-Z (google it ) and if any of the motherboard options or memory options flake than it's a good chance they're causing your problem.

Freezframe

Well if nothing else works !!!!
You may need to pull CPU !!! If there is dust in fan for CPU .....There may be dust in behind the CPU its self ..Pretty easy fix though ....There will be a build up of dust directly behind ....Simply, and delicately remove cpu clean almost paint like substance from behind Chip ,and mounting surface.....
Heat attracts dust ,and kills electronics....

Good luck : Brady