Screen won't come on

I was minding my business on facebook on my laptop when all of a sudden everything on the screen became enlarged, and then a black screen just came on with a flickering white line in the top left hand corner. I then turned the laptop off and when I turned it back on, the startup seemed normal and it got to the "starting windows" page. But once that page finished loading, the screen just turns black. I've tried turning it off and off multiple times and the same thing happens. What can I do?

I have an HP DV6-1350 with windows 7