Smartphone Questions? Ask A Smartphone Technician for Answers
First, let’s attempt resolving this issue with your Apple device by trying a hard reset, then proceed from there if that does not resolve the problem:
Disconnect the device from it's cord, if plugged in.
Press and hold your Sleep/Wake button (on the top right) and Home button (on the front) together for around 10-15 seconds.
When the Apple logo appears, release both buttons.
The next thing you should see after the Apple logo is the home screen a few minutes later.
If the above does not work, plug it straight into a power outlet and try again.