no display

[MrCoffee]

OK so you're saying the computer hangs before POST, do you see anything of the BIOs screen?
It could be that there was residual charge in your CMOS and that its corrupt, try taking out the battery (unplug your PC first) and jumping the CMOS clearing Pins. Leave it for while then put the battery back in.

 

[saumya]

Wow, thats exactly what I did and to my surprise the CMOS battery was damaged or corrupt.I have to replace it witha new one.Everything works fine now.
Thank you guys for your great help.
cheers