[Q&A] Xiaomi Redmi Note 4G LTE (dior) faulty proximity sensor topic

*problem*
If I make or receive a call on my Redmi Note 4G the screen goes blank and stays blank until the call is ended.
Whether the phone is near my ear or not.
I couldn't even click end call.

*solution*
1. Press to make a call and type the following numbers to get to the hidden menu.
2. *#*#64663#*#*
3. Go to number 7 (proximity sensor)
4. Follow instructions and calibrate the sensor

I've attached screenshots to give you and idea of what to expect.

Attached Thumbnails