Yealink T27G

Yealink IP Phones Configuring Guide
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Why doesn’t the IP phone upgrade firmware successfully? .............................................. 72
How can I verify the firmware generation and version of the phone? ............................... 72
Why doesn’t the IP phone update the configuration?....................................................... 73
Resetting Issues .................................................................................................................... 73
How to reset the IP phone to factory configurations? ....................................................... 73
Rebooting Issues .................................................................................................................. 74
How to reboot the IP phone? ............................................................................................ 74
Protocols and Ports Issues .................................................................................................... 75
What communication protocols and ports do Yealink IP phones support? ...................... 75
Password Issues .................................................................................................................... 78
How to restore the administrator password? .................................................................... 78
Power and Startup Issues...................................................................................................... 78
What will happen if I connect both PoE cable and power adapter? Which has the higher
priority? ............................................................................................................................. 78
Why does the IP phone have no power? ........................................................................... 78
Why is the LCD screen black? ............................................................................................ 78
Regulatory Notices .................................................................. 79
Service Agreements .............................................................................................................. 79
Limitations of Liability ........................................................................................................... 79
Safety Instructions ................................................................................................................ 79