Cpu automatic shut down

[dhootha]

Hi everyone
I use a 5 year old system(Desktop). Recently the cpu started shutting down automatically .When i try to restart it logs on but again the cpu gets off after a few minutes. I see the led stops glowing and fans stop working when i mean cpu shutting down. But i see the power to monitor and keyboard and mouse is still there.
Every time i open my system, I couldn't use it for more than 20 minutes. I couldn't turn it on immediately again (It can't stay for more than 5 min). However i tried to run to some temperature tests through speedfan software.

I have already tried removing the ram chip(I have only one gb) and putting it in the other slot.still the problem persists.
Here are the image links. Sorry, I didn't know any other way to share this pics.
https://www.dropbox.com/s/urwfqexqtuvgiu2/1.JPG
https://www.dropbox.com/s/qf29ob7qghbj841/2.JPG
https://www.dropbox.com/s/amtw53pqomdf631/3.JPG
https://www.dropbox.com/s/gg8e59249jtxb7c/4.JPG


I have intel core 2 duo processor.1 gb ram. gigabyte motherboard g31m-es21.I hear no unusual sounds when it shuts down.I have cleaned my heat sink and turned on the system.
Let me know if u need anymore details. Please Help me

 

[IntelEnthusiast]

I would bet that it is the PSU. Next time you have it on and it shuts down open it up and put your hand close to the PSU and see if you fell the heat coming off from it.

 

[o1die]

Either the cpu or power supply is overheating. I would get a canned air product and clean both the cpu heatsink and power supply fan for starters, then clean and reapply thermal paste to the cpu heatsink if needed. You can clean off the old paste with isopropyl alcohol or fingernail polish remover, which contains acetate.

http://www.frys.com/search?search_type=regular&sqxts=1&query_string=century+duster&cat=0&submit.x=18&submit.y=6
http://www.frys.com/product/7164172?site=sr:SEARCH:MAIN_RSLT_PG

 

[padgettnr15]

Did you reapply thermal paste after cleaning it? Also how did you clean it?

 

[o1die]

You may use tissue paper or a cloth and clean it off with the alcohol or acetate I mentioned previously. You may even do it without removing the cpu from the socket. It doesn't have to be spotless; just get most of it off. Apply a single drop of paste in the center of the lid (covering the cpu) and spread it with a single edge razor blade or simply install the cleaned heatsink (same procedure as the cpu) and let the heatsink force spread the paste around the lid.