Right side of backlight dim

Just replaced my screen with the screen from here and it worked perfectly until I put my phone in my case and then removed it again. As soon as I put bending pressure on the top right to pull it out of the case, the right side of the screen loses backlight. I open the phone again and it works again until I slightly bend the top right corner like I'm removing it from a case. I can tap & bang all areas of the phone and its perfect. So long as I don't take it out of the case, its fine. I redid the install to make sure all plugs are in perfectly and they are. Checked cables for rips and ensured I didn't open the screen more than 90 degrees. What could it be? I'm about to trade the phone in so it's not a show stopper... Just curious.