Semi Dead Panasonic KX-TGA100N with ''C533'' displayed.

The KX-TGA641 handset is not compatible with the KX-TGC350 base. The KX-TGC350 communicates with the KX-TGDA20 add-on handset. The included handsets are KX-TGCA35 (1 to 4 handsets depending on the model). See the manual here: https://help.panasonic.ca/viewing/ALL/KX-TGC350/OI/TGC364_PNQX7789XA/TGC364_PNQX7789XA.pdf . You can also check the product page here: https://shop.panasonic.com/cordless-corded-telephones/cordless-telephones/KX-TGC35.html?dwvar_KX-TGC35_handsets=1 .

The KX-TGA641 handset is compatible with the KX-TG6400 series base. See the manual for this expandable cordless telephone system here: https://help.panasonic.ca/viewing/ALL/KX-TG6411/OI/TG6411_PNQX1623YA/TG6411_PNQX1623YA.pdf?a_id=54175&session=tg2XbQ_o . You can also find the handset's manual here: https://shop.panasonic.com/support-only/KX-TGA641T.html . Additional information for the KX-TG64 series phone system is available from one of those product pages: https://shop.panasonic.com/support-only/KX-TG6411T.html .

I wish that I had better news for you. In this case, the base is speaking a different language during registration than the KX-TGA641 is expecting. They will never properly communicate.

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

it means you are not connected to the phone line. please check the rj-11 cable connected at the back of the phone base/charger.

are you using VOIP? try to turn-OFF then turn ON your router after 5minutes

thanks anyway but panasonic solved the problem with a information booklet

Sounds like the antenna on the base station is not receiving, or the cordless handset is not transmitting -OR- the sets have never been registered to the base station (please look up registering to base station, if the set has never been registered)

Did the cordless set work before?

The base station or the handset may just have a hick up, I would un-plug the base station and leave it un-plugged... now get all the cordless set(s), and take out the batteries from the cordless set(s). Wait for about 15 seconds for all the power to drain out of the sets, then re-install the batteries.

Once all the cordless sets are back up and working, plug in the base station and wait for about 1 minute.
This forces the base station to re-establish and link between the base station and the cordless sets.

Good luck

(Got this from a Panasonic Support Tech...Thanks Panasonic!) The following steps should help.... Resetting Handsets