I suggest that you perform a BIOS recovery following the instructions detailed here: http://www.intel.com/support/motherboards/desktop/sb/CS-023360.htm. When they say "Recovery BIOS", they mean the latest BIOS available for your board.
Why were you disabling AHCI?
Thanks a lot for your suggestion.
I tried the same, by downloading ML0017.BIO and copied the file in pen drive.
removed the jumper and switched on by connecting the pen drive.
But nothing happens no display.
I tried with graphics card connected to motherboard
and once without graphics card, that is using on board graphics
I didnt disable actually, I gave disabled selection and reverted back to enable.
Since I gave enable again, I was sure no changes would be made, so I gave save and exit bios(in classic mode)
But the bios got hanged.
Didnt boot after that.
Was the flash stick plugged into a port on the (back) I/O shield of the board? Don't use ports on the front (this adds another variable into the problem).
During the recovery operation, does the LED on the flash stick ever flash?
If it doesn't, unplug system from the wall. Remove the battery. One hour later, insert a brand new CR2032 battery in its place. Try things again. If you can flash the BIOS and get into BIOS setup afterwards, remember you need to hit F9 to restore defaults and then change any other BIOS settings that you need (like boot mode)...
If worse comes to worse, look at the rough procedure I highlighted in this posting: Stopped booting: how to approach?
If this works, great. If you still don't see video working, it may be time to contact Intel Customer Support; something on the board may have failed...
Nothing seems to be working.
Flash drive led doesn't show up.
No bios keys is working, because Numlock led doesnt show up or even the optical mouse doesn't glow.
I have to take it to Intel customer support.
Thanks a lot for your suggestions.
Is your problem resolved ?
Did you solve the problem replacing the board or you solved the problem following Scott's recommendations?