2007 MacBook with white display, vertical lines
The display of my 2007 MacBook periodically fades to white, very slowly, almost like a snowy TV screen. The screen gets whiter and whiter until vertical lines appear, with the display still very faintly visible behind. Firmly pressing the back of the display totally unfreezes the screen and causes the lines to disappear instantly. Any ideas as to what could be causing this?
MacBook, Mac OS X (10.6.8)