To turn on the device, press and hold the Power/Lock key until the device vibrates.
To power the device off, first press and hold the Power key.
Tap Power off.
If you are unable to turn your phone on, plug the phone 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 Power/Lock and Volume Up keys for 10 seconds, until the device reboots.