Thread: What Causes A PC To Switch Itself Off?

My PC just switched itself off I can't work out why?

So what causes are there to make a PC switch itself off?

Could be a virus set to turn it off after a certain amount of time...or it might be overheating. Sometimes PCs do this to stop the processor melting to the motherboard if it is the case of overheating. Whats your anti virus say about it? Does it report anything unusual?

might be over heating, I had a similar problem with a laptop, I have it sitting on a tennis racquet now to let the air circulate around it, seems to not be overhating as much. might be a faulty PSU.
Could be a few causes

a big doubt on the virus / spyware front lol
however it's possible for a virus to auto bat sys command line; [shutdown -s] or [shutdown -r] but it's not possible or unlikely to turn the power off.

heres 3 things to take into account;

1. Computer is overheating
2. CPU is on the blink or Overclocked
3. capacitors have blown on the motherboard

Mine did it the other day when I kept ignoring the windows update.

my money is on overheating ... my advice is to take the side panel off ya pc and get all the dust (that will be there) from under the fan on ya processor

PC just turning itself off could be 1 of a number of things, it happened to me a while back and i finally figured it was my power supply - since replacing that its been fine since

but it could be

overheating (get a temp monitor and turn logging on, also take the case side off and blow a fan into it see if it turns off again with that happening)

a faulty power supply unit (get a PSU monitor and see if powers are fluctuating and also if the rated power on the 5 and 12 volt rails are close to those voltages in reality or not, also if its a PSEU issue it is likely to only turn off when system is under a heavier load)

faulty cpu (get a test software to stress test it)

faulty motherboard (i think you can stress test your motherboard also)

a problem with the system fans (get a fan monitor and log the RPM)

With some trial and error you should be able to pin point what your problem is

Originally Posted by oothe

my money is on overheating ... my advice is to take the side panel off ya pc and get all the dust (that will be there) from under the fan on ya processor

I think i will do this first and see if this sorts the issue - although it hasn't turned off since

My anti-virus says everything is fine

Could a power-surge cause it?

a power surge could cause it but a surge at only one socket that only affected one thing is kinda uncommon

i'm willing to bet that ya got a big old load of dust on ya processor ... and perhaps on the fans in ya pc also ... you'd be amazed at how fast dust accumalates in ya pc ... i clean mine at least once a week to keep it clear

Originally Posted by oothe

a power surge could cause it but a surge at only one socket that only affected one thing is kinda uncommon

i'm willing to bet that ya got a big old load of dust on ya processor ... and perhaps on the fans in ya pc also ... you'd be amazed at how fast dust accumalates in ya pc ... i clean mine at least once a week to keep it clear

I cleaned my PC this morning - so i'll see how it goes from now.
I have also done another virus scan and am now scanning for malware just in case.

I have 3 fans and 2 were easy to clean and the third is inside a box so i did what i could with a hoover I am also thinking one of the fans (the one inside the box) might not be working. So when i drop my PC into a repair shop to put another DVD re-writer in, i will get them to check all fans and just do a general check to make sure everything is in order. My PC has done well seeing as it's 5 years old now

The last time i cleaned my PC was about a year ago Oothe There wasn't that much dust to be honest but a large clump of dust accumulated behind where the cd player/dvd rewriter are. I must start doing it monthly if i remember that is

the fan in a box as you call it im guessing your talking about the power supply fan
self contained inside the power supply unit. Never under any circumstanses dismantle the Computers PSU. You can remove dust with a can of compressed air with out having to dismastle the unit via the airflow fan hole at the rear of the unit.

The amount of distroyed computers ive seen due to some one shoving a
static fueled vacum hose on a motherboard makes me chuckle 1 little static spark
and thats the motherboard , harddrive , cpu, memory gone bye byes !

i have said before on here what a Noob mistake it is to use a hoover
electronic outlets sell special antistatic hoovers and cheaper cans of compressed air for those sort of jobs.

My best advice is if you dont know what your doing then simply dont fuck about
it annoys me sometimes when reading self help threads i mean
If i had a dodgey boiler that was leaking Carbon monoxide i wouldnt ask
people in here how to fix it and i wouldnt try to fix it myself people learn
trades and get qualified for a reason. I suggest ringing up your local failing
credit crunched IT firm and give them some business ! most wouldnt even charge
you for such procedure but word of mouth is always good for there biz.

Originally Posted by J3D

the fan in a box as you call it im guessing your talking about the power supply fan
self contained inside the power supply unit. Never under any circumstanses dismantle the Computers PSU. You can remove dust with a can of compressed air with out having to dismastle the unit via the airflow fan hole at the rear of the unit.

The amount of distroyed computers ive seen due to some one shoving a
static fueled vacum hose on a motherboard makes me chuckle 1 little static spark
and thats the motherboard , harddrive , cpu, memory gone bye byes !

i have said before on here what a Noob mistake it is to use a hoover
electronic outlets sell special antistatic hoovers and cheaper cans of compressed air for those sort of jobs.

My best advice is if you dont know what your doing then simply dont fuck about
it annoys me sometimes when reading self help threads i mean
If i had a dodgey boiler that was leaking Carbon monoxide i wouldnt ask
people in here how to fix it and i wouldnt try to fix it myself people learn
trades and get qualified for a reason. I suggest ringing up your local failing
credit crunched IT firm and give them some business ! most wouldnt even charge
you for such procedure but word of mouth is always good for there biz.

Thanks for the advice J3D - i did use an anti static hoover for the fans through the airholes Plus i didn't dismantle the box And i used a new small paint brush to brush off dust off the motherboard and circuits I'm not that stupid Although some may argue this

But it's important to others reading the thread that may at some point have to do this themselves do NOT use a normal household hoover

yeah if the PSU fan is not working, itd definatly cause issues with a cut out, most are designed to cut out if things go wroing inside a PSU, but also, the PSU fan might not spin up until a certain temp is reached, hopefully when the system gets looked at he will find what the problem is for you

Originally Posted by msprim

Thanks for the advice J3D - i did use an anti static hoover for the fans through the airholes Plus i didn't dismantle the box And i used a new small paint brush to brush off dust off the motherboard and circuits I'm not that stupid Although some may argue this

But it's important to others reading the thread that may at some point have to do this themselves do NOT use a normal household hoover

If you used a plastic Hoover you'd be ok, metal one not good, if you opened your computer and used one of those upright hoovers with the big brushes that spin around!

then your computer is definatly fooked

Originally Posted by delta9

the PSU fan might not spin up until a certain temp is reached

I didn't know that delta9 - maybe there's nothing wrong with it after all

But i'll get it checked just to be on the safe side

But everything seems to be ok since the clean up

Originally Posted by Ray Sparra

If you used a plastic Hoover you'd be ok, metal one not good, if you opened your computer and used one of those upright hoovers with the big brushes that spin around!

then your computer is definatly fooked

Could you imagine trying to use one of those stand up hoovers without the hose

Mission Impossibe

But yes i bought a anti static hoover from a computer shop

Originally Posted by Ray Sparra

If you used a plastic Hoover you'd be ok, metal one not good

actually that would be worse for static

If the fan in the power supply has stopped working, then you really need a new power supply. One of my dads mates didn't realise he needed to change it if the fan stopped & ended up with it going bang, and stinking his house out with the smell. Luckly the other parts of the pc were ok.

We got a decent psu from overclockers.co.uk, but I'm sure if u have a local pc shop that they can sort u one out that is compatible with the pc you have.

Another thing to check is the fan on top of the processor on the motherboard is going round. If this stops it needs attention straight away. Someone else I knew didn't sort it & ended up melting a hole in their motherboard!

Originally Posted by msprim

I didn't know that delta9 - maybe there's nothing wrong with it after all

hah yeah you know these hardware manufacturers dont like to keep to standards - just making it harder for us to troubleshoot

Might be a stab in the dark but did you knock the off button with your knee or summat?

Originally Posted by Thrash

Might be a stab in the dark but did you knock the off button with your knee or summat?

I wasn't near my PC at the time Thrash - i was in the middle of downloading a file too - i was watching something on telly and next thing it just turned off

Originally Posted by RenegadeGenius

If the fan in the power supply has stopped working, then you really need a new power supply. One of my dads mates didn't realise he needed to change it if the fan stopped & ended up with it going bang, and stinking his house out with the smell. Luckly the other parts of the pc were ok.

We got a decent psu from overclockers.co.uk, but I'm sure if u have a local pc shop that they can sort u one out that is compatible with the pc you have.

Another thing to check is the fan on top of the processor on the motherboard is going round. If this stops it needs attention straight away. Someone else I knew didn't sort it & ended up melting a hole in their motherboard!

I know the other 2 fans are definitely working - the one on the motherboard and the other fan underneath the PSU box - i checked

The fan in the psu box didn't start but then it may only start when the psu get's to a certain temperature - so i'm not sure - but i am getting it checked out by a professional RG

Originally Posted by Thrash

Might be a stab in the dark but did you knock the off button with your knee or summat?

I wanna know how big msprim's button is for her to knock it off with her own knee (fnarr fnarr, gernunf gernunf)

Originally Posted by swipezster

I wanna know how big msprim's button is for her to knock it off with her own knee (fnarr fnarr, gernunf gernunf)

When i first read the above i thought it said bottom

well, id love to know any woman who can knock off her button with her knee