Intermittent Screen flickering when moving lid on Dell Latitude E5420?

Hello,

I have had a problem with my Dell Latitude E5420m were the screen starts to flicker when the lid is moved. This is a intermittent problem as you can find the right position fro the lid and it works fine. I have also plugged in an external monitor to check the graphics card and had no problems. Due to this I believe the problem is the ribbon cable connecting the screen to the board. I have re-seated the ribbon cable attached the screen but I am struggling to find a way to get at it on the board, and didn't want to just start taking screws out at random till I did :)

I will upload a couple of pictures of were I have got up to with disassembling the laptop. If someone could point out the best way to go from here I would be very grateful.

Kind regards,

Chris