How can I keep my screen from going off when I am on a call on my Lumia 735?

[Windows Central Question]

Lumia 735 screen problem

Hello, i have big problem with my NEW lumia 735, when i making call for someone screen going to off and after end call is rly hard to make screen open again, sometimes i have to press button 5 times.
Actually if I dont talk, just if call screen always going off

 

[worldspy99]

Re: Lumia 735 screen problem

Your proximity sensor is bad. Take the phone to Microsoft Repair. Thanks.

 

[Piotr Michalski1]

Re: Lumia 735 screen problem

meaby but when i made self test all was ok
wake-up function too is dosent work. i can tap 1000 times mine screen and nothing.
I bought this phone 4 days ago :S

 

[Hesham Fouad]

During a call if screen go black even if phone not on your ears test this put the phone proximity sensor during a black screen call near a very hi lamp 120watt very close almost stick to it if screen turn back on then its a glue stick issue can be fixed but use your warranty

 

[colinkiama]

Re: Lumia 735 screen problem

meaby but when i made self test all was ok
wake-up function too is dosent work. i can tap 1000 times mine screen and nothing.
I bought this phone 4 days ago :S

Are you using a case or screen protector?

 

[honda accord 99]

Try to do soft reset ( VDB + PB ) one or tow times.