Why does my PC shut down randomly?

Question

I have a custom made Desktop PC which recently started switching off suddenly for no apparent reason. I am able to turn the computer back on immediately. Sometimes it can take a few hours untill the PC turns off, sometimes it does so on startup. I have tried using a different power supply and the problem still persists. I also attempted moving the ram around (in all slots and: with just the one stick as well as both together). I also used another hard drive (removed all previous drives and tested different sata ports) but the problem still persists.

My components are as follows:
Mother board: Gigabyte GA-B75M-D3H
Power supply: Hutntkey APFC 600, 600W
CPU: Intel i7 3770
RAM: 2 x Transcend 4GB DDR3 1600 DIMM CL11
SSD: Samsung 750 EVO 250GB

What could I still do to troubleshoot/ fix the problem?
My power supply makes a weak high-pitched sound even when switched off. Could this, over time, have damaged something on the MB?

All answers would be greatly appreciated.

Answer 1

Thanks for the responses. I will get some thermal paste and see from there (I have noticed that the PC stays on longer in the evenings, often being much cooler inside). Just changed the power cable but still suddenly shuts down.



I have tried a different hard drive with a fresh version of Windows 10 already, same problem. I have also looked at event viewer but nothing special appears after each shutdown, only a critical message saying unexpected shutdown. (Unfortunately after a shutdown some system .dll files corrupted and now I can't access event viewer let alone do a system reset. And I don't want to do a fresh install as I don't have the product key anymore and Produkey can't find it either).

Answer 2

I think you have to check the wire that is connected to your monitor and power supply. Sometime is loose, so it creates problem and causes of malware.

Answer 3

In my experience the main cause of this is bad application of the thermal paste between the CPU and its heatsink. over time the paste gets hard and shrinks and becomes less effective. If it was applied unevenly in the first place, when it shrinks slightly, large areas can pull away completely and leave gaps which will overheat the CPU, and it will shut itself down with no warning, and often without logging a error.



This situation can easily override the built-in throttle down since the temperature rises too quickly for safe throttling.

Answer 4

An overheating power supply, due to a malfunctioning fan, can cause a computer shut down randomly. To overcome this problem, you should check some settings like turn off fast startup, update motherboard drivers, and also update BIOS.

Answer 5

Overheat? RAM faults? HDD crash? Malware?

Answer 6

you start by getting free utilities to monitor the temperatures of both cpu and gpu. install them and then make note of the temp patterns.



ask again when you've got this info



next idea is that one of your RAM sticks is dying. And no, that noise doesn't sound good to me -- my name brand psu makes no noise other than the fan

Answer 7

you need a new cpu fan. processor will shut down if the temp is above 70C.

Answer 8

The first guy has a point. If your CPU overheats, it will shut down the computer automatically to protect itself. There are free utilities that show you the temperature of all 4 cores in your processor. There are 'stress test' programs that work all 4 cores at top speed and you can track their temperature. If this is your problem, you might only need to replace the thermal paste between the CPU and the cooler heat sink.



Another thing to try is to reinstall Windows. This is a hassle because you also have to reinstall all your applications programs and set everything up. But it's just possible that there's some malware in there somewhere that's overworking your CPU or causing shutdown as a 'side effect'.



You could do an 'idle test'. Assuming you're using Windows 10, shut down all your programs until it's just Windows running. Then hit ctrl-alt-delete and look at the Task Manager. Hit 'more details' if necessary to see the five columns--CPU, Disk, Network, Memory, Power Usage (not in that order necessarily. I'm going from memory here). CPU and Disk usage should quickly decrease to very near zero. Look at the list of tasks running--there may be a dozen or two even when the computer is 'idling'. See if they all have readable names. If you have any whose names are just random characters, that's probably a virus or something.



It COULD be the motherboard, but that's really very unlikely. Gigabyte is a pretty good brand.

Answer 9

I have seen a faulty hard drive, or a bad power supply cause this problem. If you eliminated the hard drive and power supply, and this kept happening, then they are not the problem. I would still look into replacing a power supply that makes a noise because it can damage other components.



Usually a faulty mother board or RAM would mean the computer never works at all, which is not the case here.



Could there be a fatal error in the operating system? I have had a computer that shut of randomly and after restoring the OS it worked like normal again. You can also check if something is shorting out the computer at these random times (a loose wire somewhere).

Answer 10

Is it possible that it is overheating?

Answer 11

Have you replaced the CMOS battery?

Answer 12

clean out the inside of your computer if is a desktop that will help the computer.

Answer 13

overheating, your mother board the capacitors may need replacing due to old age and usage, your power supply maybe faulty, your processor or RAM cards maybe faulty.

Use process of elimination to find the problem, replace each part till it starts working again and you should be able to find the faulty component.

Answer 14

First things first. From the Start button, get to Settings >> Control Panel >> Administrative Tools >> Event Viewer.



Open the System log and search for the time of the most recent shutdown. Look for any event logs just before (like, 1 to 5 seconds before) the shutdown and see if they call out something. You have several shutdowns so you should have several events. Look in the event logs for those events.



It is also possible for you to have other logs besides the System log. Again, look in them for the times of your shutdowns. ALL logs are sorted by time so it should be easy to find the significant times. Remember, you are looking for a call-out of something that is common to a very short time before each shutdown.



That will tell you where to start looking.

Answer 15

You have done all the right things to eliminate what you can.This is either an overheating CPU due to a faulty fan but it could also be due to a faulty CPU or motherboard or possible a loose cable shorting out. Initially Run prime95 to run a stress test and monitor the temperatures with HWinfo

https://www.hwinfo.com/download/

https://www.mersenne.org/download/



If the temps are above 85-90 then this is too high and maybe the cause of shutdowns, however the CPU normally would thermal throttle before this point to keep the CPU from overheating (and shutting down)



check all the cables, swap out the CPU cooler for another if the problem persists take it to a tech for them to swap out the CPU with a known good one.

The high pitched whine from the PSU is of no consequence and is due to coil whine (resonating).

Answer 16

Take it to a PC shop.Thermal overload. (circut breaker)

Answer 17

Check for viruses