To turn the device on, press and hold the Power/Lock button until the screen lights up.
To turn the phone off, press and hold the Power/Lock button.
Tap Power off.
If you are unable to turn the device on, plug the device into a power source for 15 minutes, then try again.
If you are unable to power your device off or if it becomes unresponsive, press and hold the Volume Up & Power/Lock button for 10 seconds, until the device reboots.