I have voicemail to retrieve and when I go to enter in my pin the screen goes blank. The only way the screen comes back and only for a second is when I jerk the phone back towards the floor. But then it disappears again and I'm unable to put in my pin. I've tried hitting the power button on the right side as well and it still disappears. Anyone else having this issue? Or is it just a defective phone? Any feedback is appreciated.