I was in the play store and suddenly my phone froze, I pulled out the battery to restart and then when I got to the locked screen I realised that my screen was not responding at all. I tried pressing down the top left corner as recommended in another thread, but that hasn't worked. I have taken out the battery and restarted a number of times. I also noticed that on one of the restarts the battery level dropped from 40% to 5%, which suggests there's not just a problem with the screen. Any ideas of what the screen problem might be?