Samsung SGH-X426ZSAAWS - Manual (Page 31)

Call Functions 27
Quickly Switching to Silent Mode
In silent mode, your phone vibrates instead of ringing
when you receive a call.
In Idle mode, press and hold until the “Silent Mode”
message and display.
In Silent mode, your phone changes the sound settings as
follows:
To exit silent mode and return to normal settings, press
and hold
until Exit Silent Mode displays.
Option New Setting
Alert Type (Menu 3.3) Vibration
Keypad Tone (Menu 3.4) OFF
Message Tone (Menu 3.5) Vibration
Folder Tone (Menu 3.6) Off
Power Off tone Off
Extra Tones (Menu 3.8) OFF