View this info if your device is unresponsive, frozen or won't power on or off.
Press and hold the Power button (located on the upper-right edge) for approximately 20 seconds or until the device power cycles. Press the Power button again for 2-3 seconds to restart the device.
If the Power button method doesn't work, charge the device for a minimum of 4 hours using the supplied charger or 12 hours if using a different charger.
Refer to Power & Charging Issues - Non-Removable Battery Devices for additional info on resolving power issues.
Related Topic: Unfreeze Your Device