Lumia 950 call function isn't working properly

[Windows Central Question]

When I make a call the Screen goes blank, buttons don't work and I can't hear the person calling me.
i called my partners phone to see if it receives on the other side and I can hear myself talking. But I don't hear anything through the Lumia phone speakers.
When I plug in head phones the screen comes back on and the there is sound in the ear pieces so I think it's a software issue but I dont know for certain.
I have already preformed a hard factory reset and it doesn't seem to have had any effect on the malfunction. I hope someone can help

 

[spicypadthai]

Have you tried replacing the SIM? Or putting the SIM in a different phone to verify it's not the problem? I'm not sure the symptoms are of a bad SIM but it's worth a shot b/c other than that, it sounds like a hardware failure.

 

[ochhanz]

I think if you press the power button (below the volume buttons) of the phone once or twice the screen becomes visible again. The other problem is probably sim or provider related.