|How old is this laptop and how much has it been used?|
If it's older, and/or if it's been used a lot, it's quite common for you to have a burnt out backlight , or a defective voltage inverter that supplies high voltage to the backlight, and either problem can cause no display at all.
A common symptom of a backlight that is failing is there is an overall tint to the screen for a while before it fails - often pink - if you have seen that, your backlight is probably burnt out.
The wiring for everything in the lid obviously has to go through the hinge. After the lid has been opened and closed a lot, it's quite common for some wires in that wiring to get broken. In that case, you MAY get a display when the lid is in (a) certain position(s), and not get a display when it's in other positions. It's common to have to replace the wiring between the lid and the base of the computer.
If any of those things is your problem, if there is nothing else wrong with your computer, if you plug a monitor into it's VGA port when it's off, then boot, you will get video and everything will be normal on that monitor.