Chosen Solution
Hey, i have a iPhone 6 with ios 10.1.1 the Device come with a Broke Display, i Change it and the new got broked. i Replace again a new Display. but now my iDevice is Turning on. and iTunes ask for the PinCode. but i have no Picture and No Vibration on this Device. i dont know if it the Touch IC or Backlight Problem. i dont want to Restore my Device on New iOS… :)
It could be a bad replacement screen or a problem on the logic board. Did you disconnect the battery before removing and installing the screen? I would try to re-install the previous, cracked screen (it still worked, right?). If that screen, which is known-good despite the cracks, works, then you have a defective replacement part. If the old screen does not work, then plug the phone into an iTunes enabled computer and shine a bright flashlight on the screen. If you see a dim image, then you blew the backlight circuit. It is also possible that you have Long-Screw Damage. This occurs when you place a longer screw where a short should go. The screws are not the same length, differing by tenths of a mm, and they can gouge into the logic board damaging traces. Either way, if the old screen does not work, then you will require a micro-soldering repair and this is a not a DIY fix.
