When putting LCD down to fit display no longer shows.

Hi all,

I am currently doing an iPhone 6 LCD Replacement that is causing me trouble. When I am trying to sit the screen down it is coming up with no display a few cm's from being fitted or when it does display it has a dark backlight issue on the right hand side.

When I take out the earpiece it works fine with no backlight issue and the display doesnt turn off when lower down.

I have currently tried the following:

Changed the proximity sensor, earpiece, earpiece shield, home button flex LCD shield and have tried another LCD and the same problems occur.

I have tried covering the earpiece shield with tape and the proximity flex with tape just incase there is interference but no luck. I have also restored the phone.

All suggestions would be very helpful, thank you.