How old is it???? Were there any error messages before it stopped working...were you installing anything when it quit....can you tell us anything about the time leading up to you found the screen didnt come on...was it off and you just booted it up???
Please supply some of this info..its very hard to make a diagnosis or offer help if no info is provided..it would be pretty much like me saying my car doesnt work...what's wrong...unless I say what it is or isnt doing and what I have tried, how couldanyone tell..not trying to be mean, its just that some info should be provided