IPhone 4s LCD wont work in right side
I've got a iPhone 4s, and after i've got the LCD display replaced from a unauthorized iPhone workshop, the screen won't work in right side. There is dead spots. The workshop did try with 4 different screens, and they all work in one hour, and then the right side of the phone is dead again. The connectors and cables has been cleaned, so far so good, but i'm lost... What can be wrong? The workshop says it can be the Touch IC, but its not possible to replace it says the guy...
So, can some of you experts give me some hints to what can be wrong?
The phone has been restored/reset/ Factory reset.