In the Silent section, the Vibrate setting determines whether iPhone vibrates when the phone is in silent mode. Vibrating is a good ... To lockthe ringer volume, tapthe Change with Buttons switch to the Off position. ... Unfortunately, keeping the screen bright enough to read comfortably extracts a heavy cost in battery power.
|Title||:||iPhone 4 Portable Genius|
|Publisher||:||John Wiley & Sons - 2011-03-16|