A factory reset of a phone will erase all custom settings and return the phone to its default factory settings.  Any custom button mappings or settings will be erased.

To perform a factory reset of a Yealink phone, follow these steps:

Step1

Locate the OK button on the phone.

Step 2

Press and hold the OK button until the display changes with a confirmation to reset to factory settings.

Step 3

Release the OK button and press the OK button one time to confirm the reset or press CANCEL to quit.

The phone will go through a reboot cycle.  Upon reboot the phone will check in with the SQUIBIT provisioning server.  If a configuration file exists in the provisioning server that matches the MAC-Address on the phone, the phone will download the file and apply the settings.