multiple screens stop working

A friend brought me her iPhone 5 to fix the screen after it got smashed, i followed iFixit's steps and got the screen replaced no problem.

However, a certain part of the screen wasnt working and after many more takings apart I couldnt get it working properly, I did realize that when the iphone was left flat for a while it started working in the section. So i bought another digitizer and replaced it again, just to have the same section of the screen not working. After many furious checks I gave up and took it to a repair stall in my mall to get it repaired. They fixed the screen however the same problem started happening in a week, it's one specific part of the screen! Now the screen hardly works, it sometimes picks up touches but has given up on the most part.

All the black tape is in the right sections and everything seems perfect on the inside!

Any help will be appreciated