Computer turns on then shuts off

[Junior6788]

I'm not sure what is wrong but when i turn on my computer it stays on for about 15 seconds it shows the compaq screen then it just shuts off. it keeps doing that. anybody know whtas wrong

i have a
compaq presario sr1220nx
intel celeron d
512 ram
2.93 ghz
80g hd

[Predacorp]

A friend of mine recently had the same problem. Check to see if the CPU heat sink didn't separate from the CPU, If you make it past POST how many beeps do you hear?

[Junior6788]

if im looking and doing this right. one seat sink is under one of the fans i took it off cleans in and just put it back, and the other one is only half put in (one side of it wont latch in anywhere) but i put pressure on it to keep it touching the chip underneath it and its still turning off. hopefully that made since haha

[Junior6788]

ok so i have find a little more to the problem which i think this might be the big issue someone can help.

i plug in the long power outlet in the motherboard and there is also a 4 square shaped outlet i plug in as well to the mb, but i just have the long one plugged in the fans start up and everything and doesnt shut down and everything. but when i plug in the 4 square one is when it does shut down