Turning a BlackBerry device off is not always an intuitive task. Unlike other devices that have a dedicated power key, the power key on a BlackBerry also performs another function, so simply pressing it once and releasing it isn't going to do anything. You can also set your BlackBerry to automatically turn off and on at different times of the day, and this setting slightly alters the overall powering off process.
Press the "Menu" button, located directly to the left of the trackball or trackpad, to bring up the application screen.
Scroll to "Turn Power Off," which has an icon that looks like a circular power button, and select it. If you do not have the BlackBerry set to automatically turn on at a given time, the device now turns off. If you do have the BlackBerry set to automatically turn on, another menu appears.
Select "Turn Off" if you want to turn the device off, but have it still turn on at the set time. Select "Full Power Off" if you want the BlackBerry to stay off, regardless of the settings, until you manually turn it on.
You can also power the device down by holding the red "Power/End" button, located on the right side of the BlackBerry, for about four seconds. If you have your device set to automatically turn on, this method will not allow you to choose the "Full Power Off" option.