Problem with Laptop Fujitsu siemens ebook series, black screen?

This is what happen , couple of months ago my laptop was running fine , one day i moved the screen down to put a memory stick behind , when i moved the screen back to where it was , it showed me a black screen like it was off , but the fan and hard drive was running fine , so i shut i off and turned on again, same black screen i let it off for couple of days , and it came ON i was so happy , but i moved the screen again just to make sure and it goes off black screen again i wanna know what going on can somebody please help