Question PC randomly turning off and then turning itself back on

[Croceus]

HI there good people of AnandTech forums. I come seeking your great wisdom, and humbly beg for you to bestow upon me your knowledge and aid.


To give some backstory, about a month ago, my pc was having a slighty similar but different enough problem. When I tried to turn it on, it would power on for about 3 seconds before turning back off. I figured it was a problem with the PSU and got a replacement via RMA, but that didn't fix it. So i took it to a pc repair place and the guy told me it was probably the motherboard. Had a spare lying around, so i swapped everything over to the new board. Boom, instant success, everything worked perfectly.


For about a month or so, it's been totally operational. However, within the last few days it has started to randomly turn off (the MB lights also turn off) and then turn back on. I've watched the CPU temp and everything seems normal, the PSU fan is spinning, windows memory diagnostic tells me the RAM is functioning fine.


I really don't know what the problem could be. Did I just get unlucky and receive a bad PSU, or have n bad MB? Is it the processor, but a non-heat-related issue?

 

[Ketchup]

Try to run a few things in safe mode (I know it's limited) and see if you run into the same issue. Try putting your RAM in different slots, if that's an option.

 

[BoomerD]

Fully wiped my hard drive and reinstalled Windows, but no luck. It was fine sitting in the desktop but rebooted as soon as I opened a few programs. Seems like something is failing when it get put under any sort of load

That sucks. Still sounds like either RAM or possibly PSU. I suspect it's a RAM thing. (but, of course, as always, I am probably wrong...I usually am...just ask my wife)

Have you tried the single stick of RAM that worked for a couple of days Looks like you have 4 RAM slots...

 

[Croceus]

That sucks. Still sounds like either RAM or possibly PSU. I suspect it's a RAM thing. (but, of course, as always, I am probably wrong...I usually am...just ask my wife)

Have you tried the single stick of RAM that worked for a couple of days Looks like you have 4 RAM slots...

I have tried that, yes. I agree that it seems like a RAM problem. Thank you and everyone else for your help so far, really appreciate it.

 

[Croceus]

PC ran for just over an hour in safe mode without any programs being run, no reboots. I'm going to get a program to stress test the PC and run it in safemode.

While I was in normal mode downloading the tester, it rebooted another 3 times during very minimal load.

It really seems like it's a hardware issue since reinstalling windows didn't fix it, but I've been running this stress tester (LinX) for a bit now in safe mode with no reboots. I'll keep running it for a while longer and report back.

I'm honestly just so lost at this point. Really appreciate everyone who has dropped by to offer advice. And especially @BoomerD and @Ketchup for sticking with me.

Might be worth noting I do have an SSD. Should I wipe that too?

 

[VirtualLarry]

Try disabling any un-needed chips or components in the BIOS/UEFI. Things like onboard sound ("Azalia audio"), LAN/ethernet (if it will let you disable it) - use a wifi dongle with your router, maybe other chips if it has any.

Also, try:
1) A different kit of RAM,
2) A GPU, something simple to start with, possibly along with #1,
3) disconnect all HDDs, SSDs, and USB devices. Try booting a Linux LiveUSB ( www.linuxmint.com ), and see if that reboots.
4) Last but not least, make sure that all overclocking is disabled, and if this system is older, consider increasing the vcore and vdimm by a hair.

It's possible to have bad RAM in the region allocated by BIOS and reserved for the iGPU on Intel rigs, which normally means that that RAM is in-accessable to RAM-test programs, even bootable ones. Using a GPU will bypass that issue, generally.

 

[Croceus]

@VirtualLarry Thanks for the BIOS advice. It seems I failed to mention that I am running with a GPU now, but I am certain that's not what caused the issues because it was happening before I had my GPU.

As for an update on the Safe Mode stuff, it's been running for almost 3 hours now with no reboots. I am going to leave it on overnight and see if it stays on.

If it stays on, would that mean it's gotta be a software issue? Would you guys have any idea what might be the problem at that point?

Again, I can't stress enough how much I appreciate everyone's help.

 

[Croceus]

Alright I just woke up and my PC still has all the files and stuff open that it did last night. That totals about 11 hours without a reboot in safe mode.

 

[BoomerD]

Alright I just woke up and my PC still has all the files and stuff open that it did last night. That totals about 11 hours without a reboot in safe mode.

IIRC, safe mode only loads the minimum drivers needed...so it COULD be a bad/corrupted driver.

 

[Croceus]

IIRC, safe mode only loads the minimum drivers needed...so it COULD be a bad/corrupted driver.

When I reinstalled Windows (I'm pretty sure) it removed all my drivers, and it was still rebooting before I installed my drivers

 

[VirtualLarry]

IIRC, safe mode only loads the minimum drivers needed...so it COULD be a bad/corrupted driver.

True... but what if the driver software is OK, but the hardware that it is talking to is flaky? That's why I suggested disabling ancillary hardware.

 

[Croceus]

Ok, here is what I have done so far & the results.

I restarted the PC in normal, not safe-mode boot mode. Ran LinX again for about 15 minutes and then left it at the desktop for another 5 minutes or so before it rebooted.

After that I went into the BIOS and disabled all the little perhipheral things I could find
I disabled:
Onboard LAN Controller
HD Audio Controller
HPET (High Precision Event Timers)
USB CONTROLLER
IGD Multi-Monitor

I then saved the changes and restarted. Then something happened that hadnt happened before, the PC started up for a second, turned off and started up again. Then it rebooted once I got to the login screen in Windows.

Something that may be relevant is that a month or so ago my PC was also having problems. It would start up for about 3 seconds and then turn off, it never got to the BIOS or Windows. I fixed that by replacing the motherboard and it worked fine for about 3 weeks before the current problem started.

 

[Croceus]

Also just booted it in normal mode again, it sat in the desktop for maybe 10 minutes and then immediately rebooted as soon as I opened microsoft edge

 

[VirtualLarry]

Also just booted it in normal mode again, it sat in the desktop for maybe 10 minutes and then immediately rebooted as soon as I opened microsoft edge

Is that with or without the LAN NIC disabled in BIOS? I'm wondering if the networking is screwing things up.

Can you boot in "Safe Mode with Networking"? Does that reboot.

 

[Croceus]

Is that with or without the LAN NIC disabled in BIOS? I'm wondering if the networking is screwing things up.

Can you boot in "Safe Mode with Networking"? Does that reboot.

I believe that was with the LAN on. I think the networking being the problem might be accurate? I'm trying to remember if it rebooted before I installed the wifi drivers...

Ive loaded safe mode with networking, but it seems like I still can't connect to wifi? The internet icon looks how it does when it's disabled, although when I hover over the icon it does say that I'm connected to my wifi and that it has Internet access.And whenever I open microsoft edge it says:
"It can't be opened using the Built-in Administrator account. Sign in with a different account and try again."

 

[Croceus]

@VirtualLarry I am going to unplug my USB wifi adapter, uninstall my network drivers and turn off the onboard LAN controller in the BIOS. Will report back

 

[Croceus]

It worked fine (in non-safe mode) with no reboots while just sitting at the desktop for around an hour, which was longer than it has been recently. However as soon as I opened the start menu and typed into it, it rebooted.

 

[Ajay]

If you don’t know how the event viewer, look it up on the web. After your computer reboots, you may be able to see what the OS logs as an issue before failing.

 

[Ketchup]

USB wifi adapter - that would have been something to mention earlier on in this thread. Can you connect to the internet without it? If not, replace it and see if that fixes your issue. Also make sure it is plugged into a motherboard USB connector, not a case USB connector.

 

[Croceus]

USB wifi adapter - that would have been something to mention earlier on in this thread. Can you connect to the internet without it? If not, replace it and see if that fixes your issue. Also make sure it is plugged into a motherboard USB connector, not a case USB connector.

Even with it and all of its drivers removed it still has the same problems

 

[Croceus]

If you don’t know how the event viewer, look it up on the web. After your computer reboots, you may be able to see what the OS logs as an issue before failing.

Will look into this. Thanks.

 

[BoomerD]

Did ANYTHING happen prior to the start of this? Did you move it around?(could indicate a loose/bad wire)
Did Windows update recently? Windows updates have been crashing PC's for a couple of weeks now...looks like you did a complete re-install though, that SHOULD have fixe that problem...unless the troublesome update reinstalled...

 

[Ketchup]

Good questions - I have two more - do you have any non-stock settings in the BIOS, and what is the PC connected to for power?

 

[BoomerD]

One more thing...that EVGA Power Supply isn't considered to be very good. Not many reliable reviews, but generally it seems like the reviews don't recommend it.

Do you have a different psu you can swap into the system for testing?

Generally, when you get a replacement for an RMA, you get a refurb unit. (Not always, but often enough) I'm of the opinion that the unit had to be refurb'd for a reason...and if it failed once...
I DO NOT buy refurbs.

Oh...and I ONLY buy Seasonic-built psu's...regardless of the brand label. My most recent unit is a Corsair-branded Seasonic. Haven't torn into the new pre-built to find out what they used...but it's highly likely it will be replaced before long.

 

[BoomerD]

Did the OP ever figure this out? Did his PC meltdown? Did we get syringered?

 

[Croceus]

Still trying to figure it out and I apologize for ghosting for a few days. Just was really over PC troubleshooting for a minute there lol.

I don't recall moving it or bumping it, or installing any new windows updates, at least not manually.

My BIOS settings are all set to default. My PSU is an EVGA supernova NEX750G, and it's just plugged into a wall outlet. I have tried other outlets.

I didn't know my PSU kinda sucks. Most of the Amazon/newegg reviews on it seemed positive. Is there a better place to look?

And no I don't have another PSU unfortunately.

Again, thanks for all the help guys. I think I'll probably end up just taking it to a local PC repair place though. I don't really have the spare hardware I'd need to see if one of the parts have gone bad.