PC powers off unexpectedly

[Marbury]

Well, yet another of my PC's , this one being brand new in 2019 has started to intermittently power off (not shut down) unexpectedly. The last couple of times was when I plugged in an old sat nav (that no longer has the now outdated software installed as it is no longer supported) into the usb but I feel this was just coincidence as it didn't happen when I repeated it.

I have ran speedfan and all are running at norm temp. I have done a check with mailware bites and CC Cleaner and nothing has flagged up.

Any ideas as it can't be the PSU being relatively new ?

[merlyn]

Have you checked if the fans are full of dust?

There will be a few fans. CPU fan, case fans, there's a fan in the PSU and maybe a fan in the graphics card.

[Hugh Robjohns]

The last couple of times was when I plugged in an old sat nav (that no longer has the now outdated software installed as it is no longer supported) into the usb but I feel this was just coincidence as it didn't happen when I repeated it.

Old sat nav... knackered battery... big initial current draw over USB when plugged in. Dipping power rails triggers premature shutdown?

Might not happen when repeated if the battery has managed to gain some recharge.

[resistorman]

Try re-seating your memory modules.

[pk.roberts]

Just in case this is a software rather than a hardware issue, I've recently come across this free little programme 'WhoCrashed' which analyses Windows crash-dump files and tries to make them a little more understandable;

https://www.resplendence.com/downloads

The download is about half way down the page, on the right.

[Marbury]

Thanks folks for all your helpful suggestions. I do believe Hugh has got something with the iffy sat nav battery as it doesn't hold it's charge long which may have caused the issue. I had no idea it could cause a pc to power off.

I will keep monitoring and see if it happens again without the sat nav. I ran the crash log but no valid crash dumps were found.

[Baldo]

WOW. This is exactly what has been happening to my W10 PC.

I posted a couple of weeks ago thinking that it was maybe an old PC form 2010.

So I cleaned up the inside, there was a little dust there. I cleaned all the fans. I even took the big cooler off the CPU, cleaned the thermal paste, applied new thermal paste and reseated everything.

I even removed a couple of old HDDs that I no longer needed.

Things seemed to be fine until today when the same thing happened again. ALL OF A SUDDEN.

The PC does not shut down. It literaly cuts the power. It is like someone pulled the mains power plug from the socket.

I did not plug anyting into the PC, I was just editing an email.

This is really really odd indeed.

[Baldo]

Just found this after a quick Google search

https://www.freecodecamp.org/news/pc-ra ... ting-down/

[Baldo]

Any further help on this??

The problem is STILL occuring for me and I can't think for the life of me what the issue could be. Really dont want to replace the whole PC un-neccissarily.

[resistorman]

Remove and re-seat all your power connectors and memory modules. Re-seat the CPU, remove old thermal paste, apply new. Swap out the power supply. Reset the Bios to default settings.

Have you checked your event logs and run MemTest86?

[Baldo]

I have done all of that resistorman. Including removing old therman paste and applying new. The problem is still occuring. It is totally random though.

[Jimmy B]

If you have tried all of that, we have to consider that there may be an intermittent hardware fault. It could be almost any part of the PC, but past experience has shown that the PSU fails more frequently than most other things. I don't like to troubleshoot by randomly swapping parts, but in this case (and assuming that this is a standard desktop PC) I would probably install a new PSU and hope for the best. If that doesn't solve it, try running it with only some of the memory installed at a time, to eliminate that from the equation, and (temporarily) replace the hard disk with one of the ones that you removed (you will have to install Windows on it, of course). Does it have a separate graphics card as well as the onboard graphics? If so, you can unplug that and run with the onboard graphics. Once you have eliminated everything else by this process of substitution, you are just left with the motherboard and CPU, which you may be able to source via eBay. (Windows may decide that you don't have a license if you change the motherboard and CPU, however).
All of this is a lot of bother, and you will need to decide if it is worth the trouble to you.

[merlyn]

Have you noticed any temperature issues? Is anything overheating? You would get an indication of that from fans spinning up. There's an app speedfan that monitors temperatures and fan speeds :

https://www.almico.com/sfdownload.php

You could use that to keep an eye on the temperatures.

[Baldo]

Thanks Jimmy.

The two HDDs that were removed are quite old. I suppose I will have to install W10 on them to see f that is the issue. The OS is currently on an Intell SSD.

I have two separate Graphics cards in there and all the RAM sockets are fully used. Not sure how I can use the onboard graphics. There seems to be no where to plug in the screen onto the mobo directly.

The PSU seems to be the logical first step since the power just comletly cuts out without any kind of warning. Its like someone has just pulled the plug out.

[Jimmy B]

If there aren't any graphics sockets on the motherboard then it almost certainly doesn't have onboard graphics. But no matter if you have two graphics cards. You can try it with just one installed, then the other. The principle is that you want to try removing or replacing each component in turn. When the fault goes away, the problem is with the component that you just took out. But you are right to start with the PSU.