Can you see any actual damage to the screen? Cracks etc. Look carefully all around.
Shine a torch on the screen. If you can see a dim image, there is a problem with backlight, inverter or cable.
If nothing, the screen or LCD cable is the culprit.
(cables/connectors could have been dislodged if lucky)
You'll need to open it up and have a look.
Have a read of a few of those and see how you feel about having a go yourself.
Post back if you get stuck or need more info.