It's just like those hallway lights that just, one stops working. But with a laptop I try the following.
I take it apart and wiggle/reseat every connection. Some CPUs in some models would work loose, but that may not apply to your model.
If that doesn't help, remove the CDROM and try again. Then remove the hard disk and see if the screen comes on. Then unplug that RAM and try again.
Tell what happens.
bob
I have a computer it was working find one day and the the next nothing. When I power it up the only thing that happens is the cd-rom powers up, you can hear it power up, the light on the cd-rom but the light by the power button does come, nor does the monitor comes on, I checked everything that I can think of. Now I am At a lost. HELP
Window XP Dell Dimension L800r

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic