My laptop shows a blank screen

Hello,
My laptop shows a blank screen. The power led comes on, the cd-rom spins for just a second,
But nothing on the screen shows up, not even the bios. The screen stays 'off'(no backlight)
I can hear the hard-disk spin silently if bring my head real close to it.
I have tried -
- removed battery and main power for a few hours
Apparently the cd-rom still works, if I put in a cd, it does spin nice and loudly but nothing happens.please help.