When calling somebody screen goes completely blank though can listen or talk with concerned person. After calling completes and call is disconnected, screen comes in when on/off switch is pressed. What to do?
Yeah... I'm guessing you have a screen protector that blocks it. There should be a little notch out of the protector, below end of the right side of the top speaker.
Yeah, this is a bit of a common thing. A lot of accessories manufacturers rush products to market just going off some rough data about the physical dimensions of the phone. That way they have something ready for sale as soon as the phone is available. Covering up the proximity sensor is usually the most common design flaw with screen protectors, and one that is easily avoided if they did their due diligence before coming to market.
When purchasing a new protector, check the description and look at the pictures... no notch, no buy.