Hi, my name is Randy. I will assist you with your Panasonic KX-TG8622. I am sorry to hear that happened to your handset. This can probably be solved with a reset,
It might be necessary to re-register the handset to the base unit. To register the handset to the base unit, you will need to access the menu then press:-
If that does not correct the problem try a system reset, follow these steps please.
A complete waste of £22. handset exactly the same - and as far as re-registering it I can't access anything let alone the menu. The other handset works on both charging units.