There are plastic tabs at the top of the screen that have to go in first. They might be bent inward, you will have to straighten them. Be careful not to bend them too much they will break off.
"I reassembled my phone, but the device wasn't closed tight enough, so the screen, on either bottom side part (above the power button), was protruding about 1.5mm up.
I ended up just making sure that those slots on the back cover were installed correctly. And then I made sure the bulging side got in first. The rest I literally just pushed hard in and it worked! I also ensured that the top part went in first because it has all those grooves."
"I just fixed my iPhone 5 and I am facing the same problem. The phone is about 1/2 mm open on the top after I closed the lower side of the phone fully. When the screen is on light inside the phone is visible from outside. The phone works well.
Not sure if I must press hard to close the upper portion of the phone but there is a risk of breaking the glass. Any suggestions"
Guys, this is an old one that you bumped, but in my case it turned out that the two upper tabs of the screen were damaged, so the screen was protruding until my iPhone's screen got broken when I was on a ride ($@$*!& mount didn't do its job), and then I bought a new screen which was easy to attach to the rest of the phone.
