Screen Going Blank During Calls on YU Yureka

Yureka recently started receiving the Cyanogen 12 update based on Android 5.0 (Lollipop). The update has however brought a bunch of bugs with it; one of them is the issue with Proximity Sensor of the device which causes the phone’s screen to turn off during an incoming or outgoing call. The issue was there in the KitKat OS as well, but it was a way less common. Anyways, while we expect YU or Cyanogen to push an incremental update fixing the issue, here’s a possible solution which should help.

Issues:

Outgoing & Incoming Calls – Screen turns off during a call
Incoming Calls – Screen turns off as soon as you receive a call making it impossible to even pick up the call.

Fixing the Blank/Black Screen Issue

The blank (or black) screen during calls is caused by the Proximity Senor of the phone. It is a hardware issue with the sensor as its detection is not as robust as it needs to be. Calibrating the proximity sensor manually can fix or at least reduce the occurrence of Blank Screen during incoming and outgoing calls. Follow these steps to calibrate the Proximity Sensor on your Yureka.

This only applies to users who have updated to CM12/Android Lollipop. If you haven’t yet, check the update instructions here.

Open the DialPad on your Yureka
Dial *#*#7769#*#*
In the proximity calibration screen, tap on Start
Wait a few seconds till it reads Calibration Good (in green)
Tap Exit.

Fix for black/blank screen during phone

The problem is caused by the incompatibility of "Adaptive Brightness" and "Color Enhancement" features.
Just swipe down from top of the screen and slide the Brightness slider towards "right" and the display should come back.
Now, navigate to "Settings->Display & lights" and "Turn Off" - Adaptive brightness and Color Enhnacment features as shown below.