My elderly mother in law has the BT4600 trio. It used to work fine, but for some reason the handsets have stopped ringing. The base rings as normal and all the handsets light up and can be answered. When you press the find phone button they all say on the display 'I am here' but none of them ring! They are all on max volume, and none have the ringer switched off. If she is upstairs she can't hear the base ringing so if we need to make sure she's up and getting ready for things like hospital appointments, we can't. This is an urgent problem for us, so I'm hoping someone can please give me any idea what the problem may be?
You could try a reset of the handsets and/or the base unit, Menu/Settings/Reset.
Don't delete the handset/base user data otherwise you'll lose your contacts.
The Customer Helpline is 0800 145 6789 if you're still having problems.