To turn on, press and hold the Power/Lock key until the screen lights up.
To turn off, press and hold the Power/Lock key. Note: If the screen immediately goes dark, you did not hold the Power/Lock key long enough. Unlock your phone, and then try again.
Tap Power off.
Tap OK.
If you are unable to turn your device on, plug the device into a power source for 15 minutes, and then try again.
If you are unable to turn your device off with the Power/Lock key, remove and re-insert the battery.