Share your experience!
When you make/answer a call the screen goes blank and you can't end the call! Any ideas?
if what you mean with "blank" is the screen goes black (just like when it inactive), try to press the power button several time until the screen turned on again.
you have something covering the proximity sensor either a protective case and/or a film
or you have an app or live wallpaper that is messing this up
uninstall all apps like utilities and see what happens
