From a Home screen, navigate: Settings > Sound .
These instructions apply to Standard mode only.
Tap Sound profile .
Tap Vibrate only.
Turning on Vibrate only mode also turns off all ring and notification sounds.
If you want the phone to vibrate and still play ring and notification sounds tap the Sound with vibration switch to turn on .
In the Vibration section:
Tap Vibration strength, slide any of the bars to increase or decrease vibration strength then tap the Back arrow to return to the previous screen.
Tap Vibration type, select an option (e.g., Rapid, Standard, etc.) then tap OK.