# PC shuts down as if the power has gone off, no pattern to it



## SHoHo (Jul 9, 2017)

Am not sure I'm in the right forum but here goes...For the past few months my PC has been switching off at random moments, as if the power has turned off. It then turns back on again and boots up without a problem. It can happen when I'm browsing the internet, or watching a film, or just using Word, or when the computer is sitting by itself with no one using it.

I am a computer ignoramus, but over the months I have tried the following:
- checked the power supply is OK (it's the the same socket as a phone which bleeps if the power goes off, so it's not brownouts)
- cleaned the fans
- installed Core Temp which checked the temperature, which was fine
- ran memtest86 - fine
- did sfc /scannow - fine
- ran malwarebytes, nothing found
- checked drivers are up to date (DriverAgent suggested quite a few intel ones were out of date, but when I used Intel Drive Update Utility it only found one, which I updated)
- did chkdsk c:/ which was fine
_However_, if I do chkdsk c: /f /x /r then it always crashes at the 10% stage.

Another possibly related clue: sometime before this problem arose, there was the issue that the PC struggled to to wake up from idle/sleep mode - I didn't manage to solve that, just changed the settings so that it the display and computer don't turn off except at shut down.

I'd really appreciate any ideas for other things to try. The family are saying "buy a new one" but seems a bit extreme, given that it functions fine apart from this.

SysInfo:
Tech Support Guy System Info Utility version 1.0.0.4
OS Version: Microsoft Windows 10 Home, 64 bit
Processor: Intel(R) Core(TM) i5-2500 CPU @ 3.30GHz, Intel64 Family 6 Model 42 Stepping 7
Processor Count: 4
RAM: 8175 Mb
Graphics Card: NVIDIA GeForce GT 440, 1024 Mb
Hard Drives: C: 930 GB (779 GB Free);
Motherboard: Gigabyte Technology Co., Ltd., H61M-USB3-B3
Antivirus: Avira Antivirus, Enabled and Updated


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## metallica5456 (Apr 1, 2013)

Almost definitely a bad power supply unit. I would replace it and see if the issue disappears.

Make sure you purchase a replacement that has enough wattage. Look on the old one and replace it with a similar wattage unit. Most OEM systems will work fine with a 400W unit.


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## TerryNet (Mar 23, 2005)

I also always think of power supply unit first. But could be overheating or a memory defect.


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## jenae (Mar 17, 2013)

Hi, yes as mentioned PSU is always suspect, you can shed some light on this. Go to search and type:- eventvwr.msc (press enter) Event viewer will open. Expand windows logs and select system, On the right under Actions select "filter current logs" now in the filter box <all event ID's> type1074,1076 and press OK. Shutdown logs will show.

See if you can locate the cause.


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## SHoHo (Jul 9, 2017)

Thank you all! I will try out your suggestions as soon as I can (probably not tomorrow....) and will post what happens.


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## SHoHo (Jul 9, 2017)

Just followed jenae's excellent instructions... strangely it isn't showing all the shutdowns (there are far too few) - but of the unplanned ones that it is showing they are all like this:

_The process C:\Windows\System32\RuntimeBroker.exe (DOWNSTAIRS) has initiated the power off of computer DOWNSTAIRS on behalf of user DOWNSTAIRS\Sue for the following reason: Other (Unplanned)
Reason Code: 0x0
Shutdown Type: power off_

So the problem is with RuntimeBroker.exe, which also seems to link back to the problem of the PC not waking from sleep. I've had a quick search and found a couple of people with the same issue, but unresolved....will investigate further. Many thanks.


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## SHoHo (Jul 9, 2017)

Hmm, it's crashed 7 times today but when I use event manager and the filter as instructed by jenae there are no shutdowns shown for today. Is there a different filter I could use to learn what's caused the power offs?


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## SHoHo (Jul 9, 2017)

Sorry, event viewer, not manager.


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## TerryNet (Mar 23, 2005)

When it's the power supply failing the computer really doesn't have time to record an event or do much of anything else. If overheating you should see an event. Not sure about memory defect.


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## lynx1021 (Jan 7, 2014)

Saw where some one said that having "*fast startup" in windows *turned on can cause problems.


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## SHoHo (Jul 9, 2017)

Thanks lynx1021, will look into it.


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## SHoHo (Jul 9, 2017)

Sorry, this one is going to remain unresolved... given how old it is I think that rather than paying someone to install a new PSU (which may or may not do the trick) I'm going to get a new PC. Though I suppose I could cut the cost by attempting to change the PSU myself and if I break it then I get a new one. In any case, thanks for your help.


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