My phone always goes dark when on a call. How do I keep screen on?

[can83]

My Samsung Galaxy Alpha (Lollipop 5.0.2) screen always goes black during a call. I often have conference calls with the speaker on, I rarely actually hold the phone up to my ear. When the call starts, the screen almost immediately goes dark and I have to tap it every couple of seconds to keep it on. I like to use my phone frequently when on calls and like to see the time, notification bar etc. without having to tap every couple seconds. I wouldn't care about this if I weren't on work calls for 6 hours out of every day.

I've tried apps with no luck (the best was 'Screen On' but it doesn't work for this purpose). My phone isn't rooted but debating looking into rooting if it can fix this error.

My settings do not give the option to 'turn off proximity sensor' so I am stuck with this issue. Short of just buying a new phone, does anyone have any ideas on how to fix this?

Thanks!

 

[LeoRex]

Is there anything blocking or obstruction the proximity sensor, like a screen protector or a case? If not, then you are in a bit of a bind.... a busted proximity sensor is a major headache.

 

[can83]

Thanks for your reply.

No screen protector or case on the phone. I've tried booting it in Safe Mode (where all the apps are disabled) but the problem persists. I also downloaded a proximity sensor testing app - which appears to show my sensor can read when things are close or far away. When I'm on a call, the phone stays on for 2-3 seconds, then goes dim for 2-3 seconds then goes completely dark. Is this normal for everyone else? Anyone have this with their Alpha?

Any apps that always keep your phone screen on?