Computer keeps shutting down.

My son's computer will just shut itself off from idle. If you are using it it does not. But does not go through the shutdown process. It just powers off.
Power supply?
Nothing of note in the event logs that I can see.
Going to sleep now. I'll check repairing the morning.
Thanks for any help you may have

This sounds like a hardware problem, in which case I've found windows event log next to useless. Get some monitoring of hardware sensors going with hwinfo

Sounds like a power saving feature being enabled. If you're on Windows 7 you can start by checking the Control Panel -> Power Options -> Change when the computer sleeps and see what Put the computer to sleep is set to.

The odd thing is that when I turn it back on it get the boot options because it did not shut down normally that rules out the power saving stuff but ill look there too.
I'll look at the hwinfo stuff for sure.

Well, it could be a bug in the BIOS somewhere, where Windows is telling the system to sleep, but it turns off. You might want to check to make sure you're running the most recent BIOS revision for your board.

I didn't think it would be the power supply at first, but after thinking about it a bit, maybe it could be. I'm not actually sure about the details of what a PC does when it goes into sleep mode, but I think it uses the 'standby' rails on the power supply to maintain its memory and enough power to come back to life when you press a key. If those rails aren't working, if the power supply is defective, the PC would think it was going into standby, but would actually just turn off.

I don't know for sure that this is what happens, but if I'm right, a failure on those rails would produce exactly the symptom you're seeing. So, maybe a power supply replacement might be in order. You can buy decent Corsair units at local Best Buys -- you'll pay too much there, but it's really easy to return if it doesn't solve the problem, so I think of it as an insurance premium, paying extra to avoid having to return something to an online retailer, which always kind of sucks.

Sadly, a full supply replacement is a big PITA that takes 30-45 minutes, so you might want to rig up a new supply on the floor or something, connect it to the motherboard and peripherals, and see if the symptom goes away. Should take, I dunno, ten minutes, as opposed to 45 minutes to replace the supply, and then another 45 to put the old one back if the problem's still there.

Replacing hardware based the details we have seems like an awfully long leap to make. Start by figuring out why it turns off/goes to stand-by/sleeps in the first place. If you want that functionality, and not just to stop it from turning itself off, then you can start debugging that when you know what it is that is failing. Stand-by handling is notoriously finicky, so it would be no surprise if doesn't work properly.

Thanks for the suggestions. I'll turn off any standby options that are on and see what happens.
If that does not have happy results then ill try the PS option.

Well all the standby options are set to off or disabled.
The hdinfo tool tells me a lot but i'm not sure how to use it.

I'll have to see if it will generate running reports until it crashes. I had it running on the screen and then I look over 10 minutes later and the screen is dark and power is off.

It won't do it when I'm sitting in front of it but as soon as I turn around, POOF.

I'll investigate the PS and see if that's it. I'm replacing my graphics card and putting my old one in this machine so it will need a more powerful PS anyways.

Happened to me too 1 month ago. See this thread and maybe it can help:

Computer Randomly Turns Off

Is this a new problem for an older PC or is this a new PC that just isnt' working right from the start?

Also, silly question but are you sure the PC is shutting down or is it just the video shutting itself off? My new Win 7 machine maybe every week or so wouldn't wake from video-sleep mode after I went to bed. I did enable the video shutoff after xx minutes in the power options, but all other power saving options were disabled. The rest of the computer was most definitely on... (numlock key was responsive) and I think the HD would spin up if I used some known keyboard shortcuts. Some combination of Win 7, my mobo or my vid card would not allow me to wake my monitor back up from sleep mode. I did a search on MS and other hardware boards and it seemed like this was happening to more than just a handful of people, but I didn't see a fix for it at the time. The only solution was a hard reset to get the video back.

To fix it longterm, I just switched to an included screensaver that pops on (the clock) and haven't had the problem since. I haven't checked boards recently so maybe a win 7 patch or maybe even a bios thing fixed it. You could try turning on a screensaver to see if that keeps it on or it still shuts down.

Do a simple test. Leave the computer as it is when it usually shuts down, but leave a book on the space key. Should be no difference in load, but if that stops if from shutting down then there's some power management option you might have overlooked.

Computers typically don't crash when idling the same way they would under load, unless there's something specific triggering it.

This is an old system that was running pretty well up until a few days ago.
It never shut itself off. Other than the odd new game it has not been given any new software.

This machine is usually on 24/7 and is rarely reboot so I still suspect power supply.
Odly, though, it will not shut off while in use. My son uses it to watch videos, play games and that's about it. He will be on it for an hour or 2 and never shuts off. Last night i was beside it while playing GW2 and it needed to be rebooted 4 times in an hour period. Would have been more if i started it each time right away.

I suspect the spacebar trick will keep it alive, but of course I want to fix that issue.

The other clue is that when i restart it it opens with the "the computer did not shut down nicely" and if I want to restart normally or into 8 different safe modes.

Picked up a new PS today. 600 CoolerMaster. was on sale. Overkill.

Any ways, I also monitored the HWInfo and the temps all seemed to be normal. Nothing was ringing any bells so heat isn't an issue, as far as I could tell. I let the monitor run with logging for a while and it never crashed. I assume this is because the machine was engaged, as if I was using it.
Only ever crashes if nothing is going on. I know, comes back to power saver stuff. Doesn't make sense.

I'll report back after I've tested the PS.

It's a long shot, but it could be related to the hard drive turning itself off when inactive. If the drive is starting to fail then it would explain the issue suddenly appearing without you changing anything and would fit with it never happening while you're logging.

Check it under Control Panel -> Power Options -> Change plan settings -> Change advanced power settings -> Hard disk -> Turn off hard disk after

Set it to never if it isn't and see if that has any effect. Again, a long shot, but should be easy to test.

Can't hurt. This is definitely a weird problem, and all of us are sort of throwing darts at the newspaper here.

And I appreciate all the darts that are thrown.
I'll check the HDD setting though I thought I did. I don't remember what it said.
I didnt get a chance to test the PS as I was installing my GTX 660 3GB!!!

SI adjusting the HD timeout didn't help
So i decided to start unplugging parts. I started with a hard drive.
it worked. It stopped shutting down. So I plugged it back in. So far so good.
I find it hard to believe that I got that lucky. I'll continue monitoring but it stayed on all night.

Well it's not the power supply, and it's not some older components in the box. I've disconnected every hdd taht's not the OS, the A drive and the CD drive.
That leaves the MB, CPU or RAM. I even swapped in my old video card.

I may have to throw in the towel at this point. I could try new RAM but then I probably would not be able to return it if it was not the problem.
MB and CPU, well I might as well wait till I get a new system in a couple months.
We're just going to save up and do that.
Oh well He'll just have to find other things to do.

Well I was going to install windows on another hd but it keeps shutting down during the process.
Seems to be hardware.

Not sure what to try next. RAM?
would faulty ram cause the machine to shut off?

Hmm, wait a minute. Maybe it didn't shut down.
This machine won't reboot. When you tell it to reboot it just shuts off.

Tried the install again and that's what it did. Booting up now and completing the install. Will keep you all updated.

Well, if it won't reboot during a clean install, it's a hardware problem.

I think you're pretty much down to the motherboard, at this point. I think you've tried everything else.

groan wrote:

Well I was going to install windows on another hd but it keeps shutting down during the process.
Seems to be hardware.

Not sure what to try next. RAM?
would faulty ram cause the machine to shut off?

Hmm. I wouldn't think RAM would cause that but wouldn't hurt to burn an iso and run Memtest

Well so far so good
It survived the night after installing the OS.

The machine won't reboot, it shuts off instead. Not a major problem but a small concern. One I can live with until I can save enough for a new machine. If I'm going to replace the mobo ill replace the lot.

My son sat down to play Minecraft and POOF! It shut off.
Back to the drawing board. I've been told if I can keep the cost down I can get some new hardware. Going AMD for price and hoping I can salvage some parts to keep it all under 300 before tax.
Fingers crossed.
Case, cpu, ram, mobo.
I know, not likely but ill try. Going to try locally first before heading out to the web.

Gumbie wrote:
groan wrote:

Well I was going to install windows on another hd but it keeps shutting down during the process.
Seems to be hardware.

Not sure what to try next. RAM?
would faulty ram cause the machine to shut off?

Hmm. I wouldn't think RAM would cause that but wouldn't hurt to burn an iso and run Memtest

Did you ever try this just to rule out the RAM?

I looked at the MB and found some of the capacitor were bulging quite badly. I also saw that even with the cover off things were actually running hotish. Cpu temps up to 50c.
I went out and got an AMD setup for under 400. Mb, cpu, ram and case.
Pretty happy with it. Working on setting it up now.

Mine was just shutting down (usually while in a game). I opened it up, and it wasn't very dirty, but after blowing the crap out of my video card and processor heatsinks/fans with that "computer cleaner compressed air cans" it's been fine.

So far everything is peachy with the new setup. It was overdue to be done anyways and this just gave us the reason to do it.
There was a lot of dust buildup in everything but he now has a computer that pretty much almost matches mine (if he had 8 GB more ram and an updated video card).