Help! PC powers off on boot

[imported_Jubei]

I just tried to boot up my PC this morning and on my first try, POST was completed and Windows was loading . . . suddenly the PC powers off. I try to turn it on again, this time entering the BIOS to check if it identifies the SATA hard drives (I have prior experience of a fried SATA controller). I do manage to enter BIOS, but after around 10 seconds, the PC powers off while I am still in BIOS. Given the limited time, I did see that the SATA drives were identified.

So my question is what is my problem? A faulty PSU??

I was using the PC less than 12 hours ago, ripped a couple of new CDs, was surfing the web and using Foobar. All was fine!

My PC : Asus P5K-E, Core2Duo E6550, 2G Corsair RAM

 

[imported_Jubei]

Problem identified after opening up case - Zalman cooler clip lever snapped in 2 and the heat sink fan fell off!!! (I use a vertical Cooler Master Centurion 5). Now that was freaky. Suppose then it is time for a new heat sink.