Answering a phone call When someone calls me I can't see the call screen but I can feel the vibration and I hear my ringtone. But the screen is total black. I have to push the lock button to wake up the screen. How can I fix it?
First go to Settings -> Apps and check if you have disable the Dialer or Phone app. If so please enable it and then check after restarting your phone.

If your Phone/Dialer app is not disabled then try these steps,


Settings -> Apps -> All(Tab) -> Dialer
Clear Cache and Clear Data
Disable it, restart phone and re-enable the Dialer app.