Hi Today i was using my phone and i noticed some black lines , i think'd that is app crash but for about 10 seconds my screen turned in to "black" or off. I tried to hold Sleep/Home buttons serval times , i tried restoring and updating but nothing happens my screen is off . p.s I can hear sounds when i plug in, vibrate works. I can connect to itunes, and everything looks fine. Please help me how to solve this.