How do I reset ringer to "on" if it is set on "off"

Page 30 of manual at the link shown suggests a way to silence the Jitterbug.

http://www.specsserver.com/CACHE/FREOWQFWSXOG.PDF

Quoting from Page 30:

To adjust the ringer volume:
1.
Be sure the phone is open and on.
2.
Press the
Up/Down
volume button
on the outside of the phone below the
display window. Press each time you want
to advance to the next choice.
These choices will appear on the screen:
- Ringer Volume Ring Max
- Ringer Volume High
- Ringer Volume Med
- Ringer Volume Low
- Ringer Volume Silent
3.
When you're satisfied with the setting,
release the volume button.
Your Jitterbug may ring and vibrate
to alert you to incoming calls. The
ringer and keypad can be silenced
by pressing the volume button
Down
until
"Silent"
appears on the screen. Your
Jitterbug will now only vibrate to alert you
to incoming calls (This can come in handy
at a movie, a library, or any other location
where a ringer may be a distraction.


http://www.specsserver.com/CACHE/FREOWQFWSXOG.PDF

My cordless is a VTech ... so not quite the same, but you need to go to menu or settings or select .. then scroll till you find RINGER TONE (not to be confused with key tone). Select RINGER TONE and should be able to scroll down to select different ring sounds. One of the options will be OFF. On mine, it is 0. Select any one of the others to make it ring. There is no ON ... if you follow my drift.
Hope this helps Tricia in Bermuda

Ringer On/Off and Ringer Volume 1. Make sure your phone is in idle mode. (not in Talk mode) 2. Press the VOL (- or +) button to activate the ringer volume setting. 3. Press either the LINE 1 or LINE 2 Soft key to select the desired line. 4. The LCD will display the volume range and currently-selected volume in an ascending series of bars. 5. Press the VOL (- or +) button up or down to increase or decrease the volume in steps. 6.The system will retain the last entry, it is not necessary to save or acknowledge your selection from this mode.
It is also possible you have set the DND (Do Not Disturb) feature which will also caution your phone not to ring when a call comes in.
Have a great day. Hope this helps.

Ringer Settings

Handset ringer volume
4 levels (high/medium/low/off) are available. The default setting is HIGH.

1. Press "Menu."

2. Scroll to "Ringer setting" by pressing up or down arrows.
then press the arrow that looks like a play button arrow pointing to the right.

"Ringer Setting"

3. Scroll to "Ringer volume" by pressing arrow down or arrow up, then press the play button type arrow.

4. Press arrow down or arrow up repeatedly to select the desired volume.

5. Press "Save."



(To turn the ringer off, press down arrow repeatedly until "off?" is displayed, THEN PRESS "SAVE.")

Here's the manual:
http://service.us.panasonic.com/OPERMANPDF/KXTG2431.PDF

Please give me positive feedback if this helps you.

Thanks.

Press CONF/FUNCTION key, scroll to Ringer Setting by using the up or down arrow of the center navigator key, then press the right arrow. Press the right arrow again at Ringer Volume. Press the down arrow to select Line 1. Press the up or down arrow to choose the ringer volume you want. Press the right soft key SAVE, a confirmation beep will sound.

The ringer volume can also be set while a call is ringing in on the line. Make a call to Line 1 number, use up or down arrow key while phone is ringing to adjust volume of Line 1 ringer.

The following link is for the manual in pdf format.

http://service.us.panasonic.com/OPERMANPDF/KXTG2740S.PDF

Assuming that this is a digital phone with a Navigator button (like 76xx or DTxxx), then press either the RING OFF soft key and the up button on the navigator button, or just keep pressing the up button on the navigator and the RING OFF will change to a level and the phone will ring.

Carl

With the phone off, press the #/pause button. The display will show "set ringer level 5", using the caller ID/volume button scroll to the level you want. Press the #/pause button to save your setting.

Here is the link to the owners manual that you can down load. Hope it helps.

http://www.retrevo.com/support/Panasonic-KX-TG2383S-Telephones-manual/id/2914ci759/t/2/

ya.. try to reset.. here is the reset code..
To restore Factory Settings for Nokia 1100
*#7780# reset to factory settings.
I HOPE,THIS SOLVES YOUR PROBLEM..

Without the exact model it is difficult to find the manual.

Here the manual for 900 series/996:Uniden EZI996.

I also quote from manual:

Selecting the Ringer Tone and Volume

Base ringer on/off
The ringer switch allows you to set the base ringer on or
off. If you set the switch to off, you never hear the base
ringer tone.

Base ringer tone
Press the ringer tone button in standby mode to select one of 7 ringer tones.

Base ringer volume
Slide the ringer volume adjuster to set the base ringer volume.

Handset ringer tone and volume
Press the volume up key or volume down key (labeled as the volume/ /+ or volume/ /- key) in standby mode to select one of five ringer tones and volume combinations