Computer turns on then off

[darrylferns]

i have a computer i built myself, has a gigabyte MB, dual core prosseror, 256 graphics and the rest of the stuff has been working fine but when i started it the other day i got into windows the shut down, i restarted it and the it only lasted about 10secs. i left it alone for a while and then the same thing. i have changed the graphics card and the psu to no avail still the same problem although the annoying little buzzer doesnt make a noise anymore

 

[CCT]

Check that the cpu heatsink is still properly attached. If that is a 775 cpu the stock heatsinks are VERY HARD to attach properly.

 

[darrylferns]

thanks mate yeah it has an asus silent knight 2 heatsink on it and the screws for the brackets had come loose all good now though