Black Screen on Startup

Hello,

My laptop worked fine the other night, however i go to turn it on tonight and it sounds like it is booting up fine, but nothing appears on the screen. Completely black. No pointer, no nothing. I have tried plugging in an external monitor but that isn't working either, also black. Not really sure what to do next? I can normally fix my own computer issues but more of a software kind of guy! Not much I can do with no screen :/
it's an Asus laptop running Vista
Please help!

Thanks,
Jack.