Thank you for your comment. From my experience, disconnecting the screen prevents damage. I have left the screen on in the past and ended up with the screen getting smoke damage. Other times I have had pieces of glass fall into the phone and get caught behind a shield, damaging the screen with a pressure spot. I have also heard of some people getting smoke damage to the camera, though I have never experienced that before. Nevertheless, because of these issues, I always remove the screen and disconnect the battery. But also, that is all I have seen to be necessary. I have never found it necessary to completely disassemble the phone before doing a back glass replacement, just the screen.