my answer phone has suddenly stopped flashing when a message is left and I am unable to hear message being left.
also some calls are not coming up with a number despite being in caller register, any ideas
Sounds like the memory is full but if it's not that you could try resetting the base unit (see page 63 at https://shop.bt.com/content/uni2/documentation/btj6/bt6600_user_guide.pdf)