Fix for iPhone display freezes, won’t turn on off, resetting, does not respond, hangs
There are many times when the iPhone stops responding, the display freezes, won’t even turn on off. For any other phone, you can remove the battery and place it back again to get it restarted. But with iPhone, the battery is moulded inside, so try the below options one by one to reset the phone.
Press and hold the Home button for at least six seconds, until the application you were using quits.
If that doesn’t work, Press and hold the Sleep/Wake button on top of iPhone for a few seconds until a red slider appears, and then slide the slider. Then press and hold the Sleep/Wake button until the Apple logo appears and let it restart.
If you continue having the above issue, Reset iPhone settings. From the Home screen choose Settings > General > Reset > Reset All Settings. All your preferences are reset, but no data or media is deleted.