Original post by: iApple ,
Hey Roberto, this usually happens when all of the screws aren't in the correct place for the metal part which is usually found covering the digitizer. Please redo it make sure the screws are in the appropriate place because you can damage the logic board by doing this. A common mistake that can cause this is that the longer screw is put in the incorrect spot or missing screws. -Let me know how it goes. -Please accept this answer if it answered the question.