First off, my phone gets a constant flow of ads with that "opt out" button in the bottom left corner, but I have learned the hard way that that can't be fixed easily. Anyways, when I am using my phone, it randomly dims and all of a sudden, the screen becomes unresponsive to my touch. I can still use the home button, the tab button and the back button, but I can't tap anything on the screen. I tried to slide the phone to open it, but it won't register my touch. If I lock the phone and unlock it, then it sometimes works and brightens, but it is annoying having to do that. How do I stop my phone from randomly dimming and turning the screen unresponsive? Thanks!