T23 PD is consistently coming up on the second handset of this AT&T Cordless phone. Then it will search for the base and come back on. Then when you go to dial the phone the phone goes dead and comes back on

You can deregister all of the handsets and then register each one again for the LS6475-3. Make sure that all of the handsets are out of the base and all chargers and that the phone and all handsets are in standby. Then press and hold Find Handset on the base. When the In Use light begins to blink, release the Find Handset button. During the seven seconds that the In Use light is blinking, press and release the Find Handset button. Wait for the deregistration process to complete (about 10 seconds).

If the process fails, you may need to reset the base. You can do this by unplugging the AC power cord to the base or by picking up a registered handset and pressing Talk/Flash. Then you can try again. These directions are on page 5 (page 8 of the PDF) of the manual for the LS6405 handset. The direct link to this manual is https://cdn-media.vtechphones.com/media/p/document2/products/%7BD6DAD9B0-4C1A-4882-93D9-04124A59B629%7D/LS6405_CIB_V5_20160805.pdf . Then check that all of the handsets are in standby and not on any charger before attempting to deregister the handsets again.

You can register 12 handsets to the LS6475 base, according to page 31 of that manual for the main unit: https://cdn-media.vtechphones.com/media/p/document2/products/%7BA37C95FC-053D-4D34-B60A-EA5ED42B056C%7D/LS6475-3_UM_4_925.pdf . If you use the cordless headsets, you can register 10 handsets and 2 headsets.

These manuals can be found through the product page: https://www.vtechphones.com/pd/1603/LS6475-3-2-Handset-Answering-System-with-Cordless-Headset . The base manual is in the section under the Support & Manuals tab. The handset manual can be found from the Accessories tab. Then click on the Support & Manuals tab after clicking the link for the Handset.

I hope this helps.

Cindy Wells

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

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"


Now you want to register the phone again.

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.
You should now have a dial tone

when I press talk I get connectin9..handset out of range..searcgin9
when I press end I get Searching

To register a handset to your telephone base
Make sure the handset battery is installed and charged properly. You have to enter a 15-digit telephone base ID to register the handset to the telephone base.

To find the telephone base ID and register the handset:

1. On the telephone base, press the MENU softkey when in idle mode to enter the feature menu. Press the or softkey to scroll to the DISPLAY BASE-ID menu, then press the OK softkey. The telephone base ID will be displayed.

2. On the handset, use the keypad buttons to enter the telephone base ID and press the OK softkey.
Press the softkey to move the cursor.

3. The handset will first display PLEASE WAIT!!, then T23 PD followed by SEARCHING FOR BASE. The screen will finally display HANDSET X when the registration is successful.
NOTES:

1. If the registration is not successful, the display will show NO BASE SUBSCRIPTION. Try the registration process again.

2. If an incorrect base ID is entered, the base ID will disappear and ENTER BASE ID will be displayed.

In case of a problem or clarification or my solution was insufficient, don't hesitate to post me a reply.

If you are satisfied, rate my solution with the "thumbs" or (even better) add a testimonial.

Well this worked for me so hopefully it will work for everyone else also... I had dropped my handset and the battery popped out.. well upon reinserting the battery i got the T23 PD Blinking error on my phone, well after trying multiple things from what the manual was stating I eventualy gave up and unplugged the handset from the wall... well we received a call in our office and all of a sudden my "unplugged" phone, that was still sitting in the handset charger began to ring and all the normal numbers and name were on the face of the handset... I then plugged the phone back in and went into the menu to Register, then entered the Base ID which is found at your Base Phone. Once this was complete it said please wait.. although for a short while it kept on saying System Busy if you tried to hit line 1 or 2 but by the next morning it is working fine! :) Hope this helps for you also.

My E2562 handset 1 would not detect base and displayed D51A PD whenever I tried to manually register it. This fixed it:
1. Remove battery from handset.
2. Unplug base and unplug phone connection(s). Wait 30 seconds.
3. Plug in base.
4. Plug in phone connection(s) to base.
5. Put battery back in handset. Handset 1 should then auto register with base.

Same problem: registering base ID on cordless get T23 PD error and subsequently, Searching for Base

I just got a 3rd handset for the same phone system and were having the same error message,,, the at&t help line does not know what it is,.,. We returned it once and got another one because of the same problems, and were still having it.. AT & T help line said to return it again and try another one .. then he actually said to replace the whole phone system .. thats easier said than done! we paid 199 plus tax on the system and then another 81.00 for the third handset!