Why does my screen go blank as soon as I dial a number or receive a call?

[Windows Central Question]

When this happens it makes it very difficult to type in my password for voicemail or to put the phone in speakerphone mode. Is there a way to prevent the screen from going blank like 1 second after dialing or receiving a call?

 

[gaita cristi]

You have problem whith proximity senzor, in that moment you tray to press the top of the screen

 

[gpobernardo]

Make sure that nothing is obstructing the proximity sensor of your phone. That can usually be found at the top of the screen to the right of the earpiece. Clean that area of the screen, make sure that there are no smudges or finger prints; if you're using an adhesive-type of screen protector (plastic, tampered glass, etc. that are pre-formed), then consider removing it (and then further replacing the protector with liquid screen variants).