ZTE Merit Z990g When I try to use in calls and I have to choose any options or put my password it doesn't work. If I call my voice mail, when it get connected with the company the screen light turn off, completely black and there is not way how to turn it on (not the phone, the screen) to use the dial pad. I press every single bottom to try to activate it back but nothing work. Until the company hang up with me, call is done and comes back again. I reset my phone 3 times already and nothing. I switched my screen light time from 30 seconds to 2 minutes to see if that helps but nothing. I really need it, I can't use it even for my voice mail. Any idea? please..