Dell Latitude D520 defaulting to external display?

There is a Dell Latitude D520 that was donated to the computer repair shop where I work/volunteer at with a very strange issue. When you turn it on, the internal LCD displays nothing. If an external monitor is connected, the image will appear normally on the external monitor, but there's still nothing on the internal LCD. Now here's the weird part: If you press fn+f8 (CRT/LCD), the internal LCD starts working perfectly! This trick works even if there is no external monitor connected. Basically, when you power the machine up, you have to push fn+f8 to get the internal monitor to work!

To sum it up, the laptop is defaulting to the external monitor instead of the internal LCD when powered up, even if no external monitor is plugged in. Fn+F8 makes the internal LCD work normally again until the next boot. I thought it might have been the lid switch, but that appears to function normally (EDIT: pressing and releasing the lid switch with your finger after booting will also restore the internal LCD video). I tried looking for a relevant BIOS setting and I tried researching the issue on line, all to no avail. The laptop works perfectly fine otherwise.

Any ideas?

 

Hmm, borked windows setting maybe, but i doubt it if the POST screen is also displayed on the external. Is there a bios revision available?

 

It's on the latest BIOS. It's definitely not a windows issue, since this issue also occurs during the POST sequence.

 

You could always remove the bios battery and see of that resets it.

 

Yeah, I think there is a BIOS setting for this as well. Like "default display" or something.