Latitude D620 - Lid detection broken

I have a Latitude D620 that always thinks the lid is closed. It started off very intermittent , with the screen flashing off a couple seconds every few minutes. Eventually it got to the point where the screen was off as much as it was on. I changed the option in Ubuntu to do nothing when the lid is closed, so I can still do my work there. But I never had the chance to do the same in Windows before it just stopped recognizing the lid as being open altogether.

I'm quite sure this isn't a software error. I don't get any image on my screen at all when I start up. I can't see any of the bios stuff or the Dell logo or any of that when I first power on. Basically I don't see anything until the Ubuntu graphical login loads.

I have another D620 that has other problems that I can use for parts if necessary. I actually already tried swapping lcd panels but that didn't work. Is there some kind of switch I could swap or something?