Somehow the display was turned off while retrieving voice mail. How can it be turned back on?

Question edited for clarity.

This phone system has two features.

Answerphone system which records messages to the unit.
and
Voice Mail System which is an extended (often paid) service from your telephone provider.

Sometimes a glitch at the Telcom will remove your Voice Mail. You will need to phone their customer service number and ask why they stopped the service you previously enjoyed? They will be able to put it back in place.

Page 32 refers

https://cdn-media.vtechphones.com/products/CS/CS6929/CS6929-X_WEBCIB_V3_20160224.pdf

Retrieve voicemail from telephone service Voicemail is a feature available from most telephone service providers. It may be included with your telephone service, or may be optional. Fees may apply.

Retrieve voicemail When you received a voicemail, the handset displays New voicemail and . To retrieve, you typically dial an access number provided by your telephone service provider, and then enter a security code. Contact your telephone service provider for instructions on how to configure the voicemail settings and listen to messages. NOTE After you have listened to all new voicemail messages, the indicators on the handset turn off automatically.

Set your voicemail number You can save your access number on each handset for easy access to your voicemail. After you saved the voicemail number, you can press and hold to retrieve voicemail. Press MENU when the handset is not in use. Press or to choose Settings, and then press SELECT. Press or to choose Voicemail #, and then press SELECT. Use the dialing keys to enter the voicemail number (up to 30 digits). Press SELECT to save. You hear a confirmation tone. • 1. 2. 3. 4. 5. 33

Turn off the new voicemail indicators If you have retrieved your voicemail while away from home, and the handset still displays the new voicemail indicators, use this feature to turn off the indicators. NOTE This feature turns off the indicators only, it does not delete your voicemail messages. Press MENU when the handset is not in use. Press or to choose Settings, and then press SELECT. Press or to choose Clr voicemail, and then press SELECT. You hear a confirmation tone.

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It is crucial to understand that Voice Mail is a
service sometimes offered by the telephone
service provider (whom we used to call "the
phone company"). This Voice Mail is totally
different from the messages we can record &
manage with an Answering Machine System.

Turning off the Voice Mail is a function managed
by the service provider's methods & procedures
and is not specific to the phone instrument itself.

AT&T, GE, Uniden, VTech cordless phones all
include an indicator light or screen display
for alerting "Voice Mail Waiting". Usually the alert
indicator is cleared (turned off) when the user calls
the prescribed telephone number and retrieves
those stored Voice Mails, but not always.

To manually reset (turn off) the alert indicator one
usually scrolls through the phone MENUs to find
a selection labled something like "VMWI Reset?"
and choose "Yes".

Specifics vary by make and model... the model
number of your phone can be found on a small
sticker underneath the battery in the handset
(eg, CS6229).

Take this model number to www.manualslib.com
to download a free copy of the User's Manual
and learn the full details of what your phone
can (and maybe cannot) do for you.

Good luck!
--

You are to contact your carrier: if they still have a voice-mail server backup it is possible.

If you subscribe to a voice mail service, you can use your phone to access your voice mailbox. The new message
LED on the handset flashes and appears in the handset display whenever you have messages waiting in your
voice mailbox. When you subscribe to the service, your voice mail provider provides you with the access number
and the required voice mail signaling tone. You can use your phonebook to store the access number

Since you didn't specify the model of your VTech phone, enter it into the search box at
http://www.vtechphones.com/vtechphones/index.cfm/support/general/manuals/
to get the manual.

I resolved the problem but I'm not 100% sure of how I did it. If it happens again I'll try it again. I left the answering machine OFF so the Voice Mail would take any messages. A friend phoned and left a message in the VOICE MAIL, I knew this because of the broken dial tone when I went to make a call. When I erased his message the 'New Voice Message' displayed on the handset disappeared. I figure a previous caller hung up just after the voice mail picked up. It was not long enough so it did not register in the voice mail but somehow registered on the GE phone. Since there wasn't anything registered in the VOICE MAIL to erase the message was 'stuck' on the handset display. As soon as there was a message registered in the VOICE MAIL that could be erased it also cleared the message on the handset.

As i mentioned, if it happens again I'll try it to see if it works, until then I am not going to tempt fate.

Your phone needs to be programmed. Look in the manual and set the buttons to do what you want. Be prepared to get confused.

is the phone totally/fully charged

The new phone registered existing voice mail. I thought it would only display incoming events. So retrieving messages from the phone service provider solved my "New Message" display quandry. Too simple.

If you pick up the handset and press the button it will call back whom ever left the message. (that extension you see.) If it is not the voice mail extension, it was just a request to have the receptionist call back. Doing so should clear the lamp.