What helped me was taking out the screen (again) and disconnect the two connectors,(put on the little rubber on the digitizer) then to make sure the lcd connector is 100% inlined I connected that one before putting the heat shield and the screws back on, Its a little harder dealing with the 90 degrees upstanding screen you need to hold still or let rest against a stander, but it ensures a good connection between the connectors, and waaaaay less changes of white screens.