While you wait for answers, we may have found some information which could help you.
Success
Message
BT 4600 phone problem?
Battery cover?
BT Studio 4500 cordless telephone?
TAM FULL on Binatone 1420 Single, base holds old messages th?
How can I mend my BT4600 (1+1) phone?
BT 4600 twin one handset bot ringing?
How do i clear the TAM?
How can i get my handset to speak with the caller?
Bt 4600 phone?
How can I repair my phone?
Mute?
Problem with handsets?