Panasonic KX-TGM420 Operating Instructions Manual page 170

Display
message
Requires
subscription to
Caller ID.
Use
rechargeable
battery.
170 | P a g e
Cause/solution
• You must subscribe to a Caller ID
service. Once you receive caller
information after subscribing to a
Caller ID service, this message will
not be displayed.
• A wrong type of battery such as
alkaline or manganese was
inserted. Use only the
rechargeable Ni-MH batteries
noted on page 9, 19.