Hello, I am working on a Dell Inspiron e1505. After a half hour or so the screen will go dark. If you move the lid back and forth the screen will lighten back up. I've set the Bios screen brightness to full. I've turned of the hibernation switches off. I even tried booting off a linux live cd, no luck. It has even darkened while in the Bios menu. I've tried everything I could think of. Any ideas?