No LED backlight after display swap on 15" MBP - HELP!

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 disconnected the LVDS cable on the glossy display from the board and found that there were two contacts completely missing from the connector. So I contacted the vendor for a return and decided while I was waiting, to put my original matte display back in. When I did, I now have no backlight on the internal video at all. I can see that the display is producing video when I shine a flashlight through the Apple logo on the back of the display and I also do have output from the mini display port to an external monitor. 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. I did have to swap the plastic clutch cover for the hinges because the new display did not include one. Could I have pinched or damaged a cable related to the backlight? I assume the backlight is powered through the LVDS cable as that's the sole video related cable on the display that connects to the board. However, there are several ribbon cables below that clutch cover too. Any thoughts on what might have gone wrong would be highly appreciated. Not a newbie doing these types of repairs either.