Can you connect an external monitor to the laptop? If so, does that work? You might need to push a button on your laptop to switch from laptop screen to external screen (read the manual on how to).
If both screens don't show anything, your VGA chip might be dead. Happens frequently with laptops, because they get to hot.
Might sound strange but try to take out the memory and put it back. If that doesn't change anything, then it might be a bad monitor cable.
Try to close and open the screen a few times, maybe then after a few times the screen might come back.