Yu Yureka - How to fix screen going blank in CM 12

You might be facing this screen going blank issue if you’ve just update to Cyanogenmod 12, a custom Rom based on Android Lollipop 5.0. What happens is your phone’s display will go dark when you receive a call or when you are in the middle of the conversation. When you are getting a call you can hear the ringtone but the display stays blank. Sometimes your screen turns off when you are dialing a number. This appears to be a proximity sensor related bug that turns off display abruptly. To fix it you will need to manually calibrate the sensor. Micromax Yu Yureka is one these devices affected by this issue. If you are one of the Yureka users or someone facing similar issue these steps might help you solve the blank screen while receiving call issue:

First: Check to see if you screen protector is causing this issue. Poor screen protectors or dirty ones can also interfere with the proximity sensor.

How to fix blank call screen issue in Cyanogenmod 12

Open dialer (click the phone icon)
Dial *#*#7769#*#*
You will not be directed to “Proximity Calibration Info” screen
Select “Start”
Wait till it shows “Calibration Good”
Now you can stop and exit

That should properly set your proximity sensor so that you won’t get a black screen on call or while getting a call. Besides Yureka, devices like Micromax Canvas A91, A110 Canvas 2 have also reported this screen bug. If you have any other fix or solution for this issue please mention them in the comments.