Geschiedenis van "Touch Screen not working proprely"

After replacing my broken touch screen and display I noticed that the touch screen isn't responding correctly to my actions. For instance the back, home and minimize buttons don't respond or when typing a message it presses random letters. Do have any ideia why? Is it a defectuous touch screen or some other hardware danificated?

Toestel:

Sony Xperia M2

Status:

open