I have a Dell Latitude D820 that I dropped while in its carrying bag so it wasn't a real hard landing. Now the backlight won't come on. I swapped an entire screen assembly from an identical D820 and it still won't turn the backlight on. I swapped the screens again and the borrowed D820 still works fine and mine won't work. (I didn't bother to test my screen in the borrowed D820.) I can run an external CRT with mine and I can see the LCD display if I shine a light on it so I know the display is working and not cracked. The laptop won't drive the CRT unless it thinks the lid is down so, to use the keyboard, I removed the sense magnet from the lid and taped it to the place where it would be with the lid closed. I've noticed in the past that this D820 often stayed fully on, including the display it seemed, when I closed the lid and walked away for hours. (Note: When I tested the borrowed screen I had the sense magnet removed.) When the magnet is taped in place (simulating lid down) both the backlight and the display are off. I can't see the display even when a light is shined on it, but when the magnet is removed (simulating lid up) I get the display with no backlight. It seems like the display knows whether the lid is up or down, but the backlight seems to act like the lid is always down. Is this possible? What should I look for?