MacBook :: When I Move Screen Up Or Down A White Thin Line Flashes Across The Screen?

there are two things that the macbook is doing to me. one is that sometimes when i move the screen up or down (the hinge is rather stiff) a white (thin) line flashes across the screen. but recently, while randomly browsing through the internet, the screen almost... i guess faded to a gray screen, but like gradually, and not like a kernel error, like the display just faded away. happened twice in a row, did a battery pull and now wont do it again.