Pc not on

Hi,
The computer was working fine till suddenly it powered off abruptly.. I don't know how it got powered off. But after that my machine does not POST. I see nothing appearing on the screen. Keyboard, mouse nothing is detected. Also there are no beep sounds. But guess i never heard the BIOS beeps when the PC worked fine.

The CD drive opens up if i only connect the power supply to it without any connection of MB to it. The fans are running and also the green light on the MB is on. But other than there is no activity.

I opened up my CPU and removed the processor FAN. Removed the grease from teh interface between the processor and the processor fan. Hope that is not a problem.. :(

I have searched the MB for any damaged/bulging capacitors ... have not found anything yet. :)

I have also tried removing the CMOS battery and booting. But no help.
Also i have tried to boot the PC with BIOS safe mode. Still no help. :(

I would really appreciate getting some help regarding some solutions to this problem. I have searched the net extensively but have not come up with worth while solutions till now.