A22p, UXGA -> SXGA+?

[jarkko]

I have a A22p (2629-USG) with UXGA lcd (droven over by a car...), and I have a spare machine A20p (2629-6TG) with working SXGA+ lcd. As far as I see the motherboards are the same, including the video controller.

So I swapped the SXGA+ lcd to the A22p, but it seems dead. No flashes or anything when powering up, even the OS (WXPP) won't see or recognize any other display than the external one I'm using. It's like there's no lcd at all.

Any advice? Tried updating the bios but no luck.