PC Turning Itself Off and On After a Long Period of Being On?

Hey,

My PC seems to be turning itself off and then coming back on again after a few seconds. This doesn't happen regularly, but it seems to happen after my PC has been on for a prolonged period. I'm talking about five hours or so. It only seems to happen once as well and then not again for quite a long time.

I was thinking it may be my power supply as I have now had it for quite a while. However, wouldn't it be more frequent if this was the case?

There is no blue screen or error message, it just turns off like I have switched the power button. Then the PC comes back on again automatically.

Maybe overheating? My PC is fairly clean as I maintain it so it can't be dust build up causing it.

Any ideas on what is causing it?

Thanks

Another thing to add, it doesn't seem to happen just when I am gaming. It has a few times but only at the same regularity as other times it has happened. Nor does it become more frequent when I am gaming. Which is weird as that is when I thought it would occur more if it was a power supply or overheating issue.

Try running prime95 and furmark at the same time and monitor your temperatures.

Using the Prime95 blend test my processor reached 80-85C on different cores.

GPUs were at around 60C on the Furmark stress test.

No shut downs of my PC, though.

Right now i have your problem also happening to my old 2007 Sony laptop and im not quite sure what it is yet, did memtest on it, and no errors, and it turned off once the other day. I can't see any heat problems but i should do a longer stress test sometime to see how hot it gets.

I got an IRQ not Equal error also once, so thats why i did the memtest. Maybe its hardware is starting to fail. Best case would be if its just the power supply or memory, that i can fix easy.

Both times this happened was when i was transfering a file through its wireless network card to another PC, so i guess maybe the wireless card or hard drive could be causing a problem... still seems to point to memory though even though it passed the memtest...

Could also be windows 7, i haven't reinstalled it since 2009.... and gotten and fixed ton of viruses and other bugs in that time period.

@PcGamingRig: is it actually doing a full restart or just going into sleep and being awoken?

@Yams1980: I have Windows 10 and it has only been installed in the last few months. It has been working fine since a few days ago though. I don't think it is my OS.

I am wondering whether to get a new PSU, but it doesn't really make sense if it shuts down when idle and it doesn't always happen while at 100% load for a decent period.

@zaku101: A full restart.

@PcGamingRig: If it's a normal restart make sure to check if you don't have a task set to do it in the task scheduler.

If it's just turning off abnormally and turning back on then it's probably the PSU, it could be having issues being under a lower load.

Go ahead and try this to test it.

Go into your power setting and set the cpu minimum processor state to 100%.

If it doesn't do it after making this change, it's probably the PSU.

Also it could be an issue with the power strip it's plugged into.

It could be windows 10 doing updates also. It'll do a auto restart like 3am or something, unless you are around to setup a restart time. Its the reason i stopped using it on one of my PCs. Forced updates and privacy invasion, no thanks.

I remember this awful OS restarting a bunch of times when i had a lot of unsaved work i had done and lost hours of work to get back on track. Ended up having to disable the update service was the only way to prevent this and eventually got fed up with the whole OS and went back to windows 7.

@Yams1980: Updates usually do the shutting down process though, not just switch off the PC.

@zaku101: Would disabling SLI stopping it from happening suggest it is my PSU. causing the problem? I disabled SLI through Nvidia CP and it hasn't happened since then.

I will also try your suggestion. If it is my PSU it will not be too bad as I have been wanting to go full modular for a while to improve wire management in my case.

@zaku101: That setting was already on. I guess it was because my PC was on the high performance power setting. So it has been happening while that setting is on, not really any way to judge by that.

@PcGamingRig: Try changing the "Power management mode" in the Nvidia control panel to "Prefer maximum performance" and leave SLI on to see if it's still happening. It might be related to it...

It's located in Manage 3D settings, Global Settings.

Could be an OC that has degraded over time, you are running the first gen Haswell which got seriously hot when OC'd so it sounds like the silicon has started to go bad. Try running on stock clocks and volts and see if it does it.

Well, since I disabled and re-enabled my SLI it hasn't happened once... Nvidia CP is now on prefer maximum performance and there is no issues.