Ok my computer was running fine but suddenly started to shut down when playing a demanding game with graphics set high. After cleaning the fan and heatsink area on the graphics card and elliminating large amounts of dust and turing the graphics down slightly this problem was fixed until . . .

I moved my pc back home from uni and set it up. Now after varying amounts of time my pc just cuts out and turns itself off completely!! It has happened from anywhere from 3 minutes of being on to up to 30 mins, but never has been able to stay on for LONGER. Why could this be happening suddenly as it has been running stable for so long? It occurs on both windows vista and xp.

Any help would be very much appreciated,

Jonny

Spec:
Dual Booting Vista Ultimate and Windows XP
AMD Athlon 3800+
2GB DDR Ram
ATI X1950XT
Nforce 4 Motherboard
2 IDE Hard drives.
Jonny, Welcome to CH

The fact you moved the computer leads me to believe that the heatsink may have moved and is not flush with the motherboard.

You might want to D/L Speedfan to check your temperatures.....when you cleaned your heatsink did you REAPPLY thermal paste.

If no luck then a swap for a known good power supply is another option....the supply could be on the way out, but the temps need to be checked first.Also try to blow a fan on it and see if that helps anyHey thanks for the quick replies. I cleaned the heatsink and the CHIP on both the graphics card and the CPU and reapplied thermal paste to both of them today. The computer was running great for about an hour and a half (leading me to think the problem was fixed) but it then just cut out once again! 

Could the power supply REALLY be on the way out? Is that the most PROBABLE reason for the malfuncion now?

I will try to check temperature of the CPU later by the way, to let you know what it is.

Thanks

JonnyFirst check the temps and post them here.  If they are ok then its probably the powersupplyOk i installed speedfan and this screenshot should give all the temperatures needed. This was recorded on my xp partition at idle. The temps would probably be much higher when on vista.

[attachment deleted by admin]Well, the temps don't look bad......reseat your memory, check all connections, and then try swap the power supply....your 12V is running at 5.82V.Yeah i didn't think they looked like much to worry about! I resat the memory today and have been forever checking connections since this started happening about 4 days ago now. Looks like i'll have to buy a new power supply! :-( I was looking at http://www.ebuyer.com/product/124927 as the power supply to get, does that look like a sensible choice? They also do the same one in a 500w edition could i get away with just the 500w one? or would i be better off going for a better brand such as antec or hiper?Jonny, I'll let someone else respond to that one.......Artic power? Never herd of them so I would say no.  Are you in the uk I am guessing? http://www.misco.co.uk/applications/SearchTools/item-details.asp?EdpNo=262111&CatId=370
That should power your computer just fine