AT&T 52251 handset not registering

Suggest you reset handset and register again with base.

Instructions from manual...
Resetting Handsets If you have trouble with a handset or if you want to replace one, clear the registration information from the base and the handset: 1. Press & hold END and # at the same time until you see the System Reset menu. 2.If you still have the base the handset is registered to, select Deregister HS, then select the handset you want to reset. If you don't have that base anymore, select Base Unavailable. 3. To confirm, select Yes. The handset displays Handset not registered. Registering Handsets If you see a "not registered" message on a handset, you must register it to a base before using it. 1. Place the handset in the base; the display should say Handset Registering. 2.Wait until the display says Registration Complete (about 30 seconds), then pick up the handset and press TALK/FLASH. 3.If you don't hear a dial tone or the display says Registration Failed, charge the battery completely, then try again.

Registering a Handset

If you see a "not registered" message on a handset, you must register it to a base before using it.

1. On the base, open the menu and select "Register Handset"

2. On the handset, press and hold POUND (#) until the handset display says "Handset Registering" (about 2 seconds).

3. Wait until the handset display says "Registration Complete" (about 30 seconds), then pick up the handset and press eND/CleaR.

# If you don't hear a dial tone or the display says "Registration Failed" charge the battery completely, then try again.

This sounds like Handset #1 has lost its "registration" with
the base. De-registering & re-registering is often easy.

First, be sure the handset battery is well charged as a
weak battery will interfere with the registration process.
Then try this ( 'works for the D1680, D1481, & similar):

To deregister the handset:

1. Press and hold the [END] and [ # ] keys at the same time,
after a few seconds the display will say
"System Reset, Deregister Handset"
press [SELECT]
scroll to "Base Unavailable"
press [SELECT] (chirps) press [END]
display reads "Place in base..."

Next, to re-register the handset:

2. Set the handset into the base cradle and wait,
within ~30 seconds the handset should display
a "Handset #" and be good to go.

Good luck!
--------------

This sounds like the handset has lost its "registration" with
the base. De-registering & re-registering is often easy.

First, be sure the handset battery is well charged as a
weak battery will interfere with the registration process.
Then try this ( 'works for the D1680, D1481, & similar):

To deregister the handset:

1. Press and hold the [END] and [ # ] keys at the same time,
after a few seconds the display will say
"System Reset, Deregister Handset"
press [SELECT]
scroll to "Base Unavailable"
press [SELECT] (chirps) press [END]
display reads "Place in base..."

Next, to re-register the handset:

2. Set the handset into the base cradle and wait,
within ~30 seconds the handset should display
a "Handset #" and be good to go...

Good luck!
--------------

Easy to do, even if the new handset is used & orphaned from
its original base...simply de-register it from the old base and
re-register it to your base.

1. To de-register the orphaned handset from the old base:
When the orphaned handset says "Connecting..." or "Out of..."
enter *331734 [menu]
and it will soon beep and display "Not registered"

2. To register the new handset to your base:
press the "Handset Locator" button on the base and hold
it until the "in use" light comes on ( ~ 4 seconds ),
then release the button and set the new handset into
the base phone cradle. After ~ 30 seconds it will beep
and display "Handset #" (next in sequence).

3: Note: the base handles a maximum of 12 handsets.

If your system was fully populated ( ie, a handset is
already # 12 ) you will have to clear all the handsets
from the base and re-register them all in sequence.
( it is the only way to 'rescue' the places occupied
by the lost handsets ).

To clear the base of all registrations:

1. Press and hold the the "Handset Locator" button
until the "in use" light lights and then starts to blink
( ~ 10 seconds ), release the button --
then press it again briefly while the "in use" light
is still blinking.

2. The base will beep and all handsets that were registered
will display "Not Registered"

3. Follow the instructions above for each handset
in turn to re-register them:
press "Handset Locator" ~ 4sec ( in-use light on ),
set handset into the base cradle, etc.

The manual is available from: www.manualslib.com
but does not fully describe these procedures.

Good luck !

The errant handsets must be de-registered from their
original base and then registered to your base.

NOTE: the CS6649 handles a maximum of only five
handsets. If you have a handset displaying
"Handset #5" then you have a 'fully populated system'
even if you actually have only one or two handsets.
In that case, you can clear each handset ( I ) then clear
the base of all registrations ( II ) before re-registering
each handset ( III ) up to the maximum of five.
=====================================
( I ). First, to de-register a handset ---

0. Start by taking off the battery compartment cover.

1. press [menu]
2. scroll up/down to "Settings"
3. enter * 7 8 9 0 #
4. scroll down to "next page", press [select]
5. scroll down to "Register Clear?", press [select]
6. display asks "Confirm?" or "Register Clear??",
press [select]
7. display reads "Ok" and chirps, press [ off ]

8. UNPLUG THE HANDSET BATTERY
(this is why the cover was off)

9. Wait ~30 seconds, re-connect the battery &
replace the cover

10. display reads "Not Registered"
===============================

( II.) To clear the base of all handset registrations
( if needed, else skip ahead to ( III ). )

1. press [Find Handset] on the base and hold
past ~4 sec when the "In Use" lamp lights, at
about 10 secs the "In Use" lamp will begin to
blink. 2. release the [Find Handset] button momentarily,
then briefly press it again. After a moment,
all handsets that were registered to the base
(if any) will display "Not Registered" and be
ready for fresh registration ===============================

( III.) To register each handset to the base:

1. press [Find Handset] on the base and hold for
~4 sec until the "In Use" lamp lights.
2. press # on the handset and set the handset into
the handset cradle on the base
3. within 30 seconds or so, the handset will either
chirp and display "Handset Registered", then
"Handset #x" or it will say "Registration Failed".

NOTE: the battery must be well charged prior to the
registration process, a weak battery may cause a
"Registration Failed". Charge the battery for a
few hours and try the registration ( III ) again.

===============================
Good luck !!

Found out how to change the handset number [1] [2] [3] [4] etc on a Panasonic Cordless handset

Panasonic KXTG6644B

Changing Handset Number:
Deregister two Handsets [#1 & #2] 0r [#3 & #4] etc

On each handset hit -
[MENU] # 1 3 1
[ERASE] [YES]

(This leaves and open space on the base unit)

Re-Register 1st Handset [#1]
[MENU] # 1 3 0
Hold [LOCATION] on Base Unit 5 Seconds
Place the Handset you want #1 in Base Unit

Re-Register 2nd Handset [#2]
[MENU] # 1 3 0
Hold [LOCATION] on Base Unit 5 Seconds
Place the Handset you want #2 in Base Unit

First de-register by pushing # and end simuntaneously. Select de-register. Then place on the base until it says that it has registered. Uniden Registering

When the handset is searching for the base, click the new button, then enter the 15 digit base ID number into the handset.

Hold the power key & the * together for 5-10 seconds. De-register handset/base. Off ya go