LCD Backlight turns off after booting through grey screen
I have a MacBook Pro 15" that I just had the hard drive go bad. I put the new drive in and booted from the install DVD. After the computer boots passed the grey apple screen the backlight turns off. I can see the install menus and successfully reinstalled Leopard without the backlight. Is there a light sensor or lid sensor that may be missing or misaligned after replacing the hard drive that could explain why the backlight turns off? I have closed the lid, put the machine in sleep, attached an external monitor. The backlight doesn't flicker so I really feel like this is something easy I may have overlooked. I have replaced lcd's in laptops before as well as hard drives in MacBooks without this issue.
If this is the same problem I just solved, if you were to plug in an external monitor it would boot to that even though the lid open when you power up the system.
Reason: it thinks the lid is closed. This was due to corrosion on the motherboard interface for the small circuitboard that detects the magnet on the left side of the LCD assembly when the lid is closed. The circuitboard also interfaces with the battery connector and is connected to it with a wiring harness.
You can leave the screws for the battery connector in place but you must remove the keyboard/touchp