What do I do to turn on the ringer of a norstar?

SOURCE: turn ringer on T7316

T7316 Manual

The volume control adjusts the handset, hands free, headset, and ringer volume. Someone may have fiddled with the buttons and turned the ringer down enough that it doesn't sound when a call is incoming.

SOURCE: Norstar Meridian how to turn on the ringer

From the following web site:

http://www.telephonemagic.com/phone-support/norstar-feature-programming-code.htm

To Change the Ring Volume:
1. Press the Feature button, then * 80
2. Press the volume key up or down
3. Press the release key1 to exit and save the volume level