Yealink SIP-T28P - Manual (Page 151)

Troubleshooting
139
2. Press or to scroll to Reset to Factory, and then press the Enter soft key.
The LCD screen prompts “Reset to factory settings?”.
3. Press the OK soft key.
The LCD screen prompts “Resetting…Please Wait!”.
The LCD screen prompts “Welcome Initializing…Please Wait”.
The phone will be reset to factory sucessfully after startup.
Note Reset of your phone may take a few minutes. Do not power off until the phone starts up
successfully.