Most LG phones have a vibrate mode shortcut button on the keypad. The vibrate mode button is easy to press by accident. Once vibrate mode is enabled on the phone, no amount of adjusting the volume will get the phone to ring. You must turn it off by holding down the vibrate mode shortcut button.
Look for the vibrate mode symbol at the top of the screen. It usually looks like a phone handset surrounded by lines.
Examine the keypad on the phone for a matching symbol. It is usually located on the * or # key.
Press and hold the button for about five seconds to turn off vibrate mode.
Release the button when the vibrate mode icon disappears.
If your phone is locked, you will need to unlock it before you can disable vibrate mode.