LG GS390GO - Manual (Page 20)

General Functions
15
You can also adjust the feedback your phone
gives when you touch/tap the touchscreen.
Touch the Touch tab, then set the sound and
vibration settings. Shortcut to Vibration Only Mode
Vibration Only Mode can be activated by
touching and holding
from the dial pad.
You can also set Vibration Mode by pressing
and holding down side volume key as well.