I'm Having Problem with Intel DG33FB

hi all I am having a problem on my Intel DG33FB motherboard this is what happen

I was playing need for speed undercover last night nothing happened wrong the pc was working fine than I shutdown the pc because I went to sleep so I shutdown the pc and unplug all the power codes

In the next morning I put all the power cables and I switch on the pc but it dent switch on all the power cable was connected and then I removed the casing and saw that the PSU fan is not spinning but the light in the motherboard is lighting it mean the power is coming but my pc is not working or the psu I cant understand what is the problem is so I decide to use a another psu the psu is in a good condition so I plugged it to my motherboard and tested it the same thing happened then I removed my old psu and tested it in another computer my PSU is working fine the problem s in my motherboard I don know what happened can any one help me to fix this problem thanks.

Note : I tried all the components(HD,DVD,VGA) removed and tested the moththerbord the same problem was spotted…

This is the system witch I have

Processor : Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz
Mainboard Model : Intel DG33FB
Memory DR 2- 4Gb
Video Ram : Geforce 250GTS 1GB (PCI Express)
Power supply : 500 W

O/S : Microsoft Windows XP Professional

Thanks

M. Asif

thanks for replying but if its a CPU problem wont i get any warning symptoms before its crash.....well i have given the motherbord to the shop i wer i bought it thay sed that thay will look up and let me know...

thanks for replying i am soory to say that i tried that one also nothing hapen....i have sent it for the replacement may be i will get the replacement on this 6th this month do u feel it might be a CPU problem??