turning off/on

hi all, i've been having some problems with my pc turning itself off,its been happening for a few weeks and i havnt been able to stop it.at first i thought it was a virus due to me having software problems aswel so i reformatted and it seemed ok,a couple of days later it did it agen.i looked on this forum and someone suggested extra cooling, i bought an additional 80mm fan and fitted it in the side of the case, ive now got two and the heatsink,it was working ok and today it did it agen(twice) i usually have to remove the mains power for a minute then turn it on agen before it will start but this time i left it and it turned itself back on after a few minutes.any suggestions welcome.thanks

 

It does sound like it could be an overheating problem.
You might want to check and see if dust has accumulated at any of the vents (particularly at the Power Supply Fan).

 

il try to give it a clean and see if it works.thanx

 

Welcome to MajorGeeks. It may also be a power supply issue. Faulty capacitors, a dying fan, too much dust build-up are prime examples of things that can cause symptoms like yours. I had a power supply once where the fan went out and I didn't know it. The PC would run fine for maybe 20 minutes, maybe 40 minutes, then it would just turn off. It would always turn back on a few minutes later, but would always shut down again. Then I got in the case and while I was looking around I happened to touch the power supply and felt how hot it was. I was really happy it wasn't the motherboard or CPU! A new decent power supply shouldn't be more than $40 or $50 (US). If you have a high-end system and are doing some serious gaming, a high-end serious power supply is strongly recommended if yours needs replacement.

Good luck! Keep us posted......

 

ive cleaned out my psu, heatsink and case fans, the grill under the heatsink was full of fluff and dust, think that may be the cause.cheers