Why doesn't my screen work even after installing a New Digitizer?

[Windows Central Question]

Hi, I have just finished installing my Nokia Lumia 520 Digitizer but I have few problems with it. The digitizer works but if I switch my phone of and start it up again it stops working and I have to factory reset it by using the buttons to make it work again.

Could someone please explain me why my digitizer stop working if I switch of my phone. I've been with the charger in my pocket all time now to make sure that it doesn't run out of battery.