If the icon in the display next to your name is red, then you are no longer registered on the server. A simple fix that frequently works is to reboot your phone. If your phone is registered, and it is still not ringing please verify that the ringer has not been turned off by following the steps below.
- On the directional pad on the phone press the center button
- Press 5, or use the direction buttons to select Preferences
- Press the center button on the directional pad again
- Press the down key twice to select Sounds
- Press the center key or Select soft key
- Verify that the ring tone is not set to “silent” and the ring volume is higher than 0