Panasonic KX-TCD510ALV Service Manual page 17

* : If the current 4-digit PIN is forgotten, press and you will
be able to enter new Handset PIN.
This password is useful whether Base Unit and Handset are linked with or not.
6.6. Reset
6.6.1. Base Unit
You can reset all of the base unit settings to their initial settings.
- To exit the operation, press any time.
Base Unit Initial Settings
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