No output to built-in display. Tried the basic stuff. What now?

So I just tried to replace my high-res matte finish display with a glossy standard-res display. The install went fine but the machine wouldn’t boot. I diconnected the LVDS cable on the glossy display from the board and found that there were two contacts missing from the connector. So I contacted the vendor for a return and decided while I was waiting for a replacement, to put my matte display back in.

When I did, I now have no internal video at all but do have output from the mini display port. All cables are properly seated and I even cleaned the LVDS connector on the old display and it’s accompanying socket on the board with isopropyl alcohol and compressed air. Was static safe the whole time.

Any thoughts on what might have gone wrong would be highly appreciated. Not a newbie doing these types of repairs either.