|If you never ever see anything whatsoever on the screen it is a hardware fault.|
Assuming the above and if the computer sounds as if it is booting up normally then it could be:
The connectors at either end of the cable between the mother board and the screen, the cable, or even the screen itself.
With the computer booted up try moving the lid back and forth slowly. If you suddenly get a glimpse of a picture then it is most likely cable failure at the hinge, or maybe connectors loose.
If you see anything but black on the screen during bootup then this could be a different matter.
EDIT: Tidied up wording.
Always pop back and let us know the outcome - thanks
message edited by Derek