Chosen Solution
Every Lumia 930/ICON have a problem with proximity sensor: Black Screen while calling , Double tap not working correctly.
Try cleaning the area around where it says “Nokia” on the front, that’s where the proximity sensor is. It also fixed the issue with double tap for me. (source: /u/Jealy on reddit)
touch screen not working
Cleaning the area on the front did not help. The display is not working while calling.
Recalibrate sensor with Nokia Care Suite.
