Yealink SIP-T20, User Manual, Page: 109 / 126

Troubleshooting
97
This chapter provides general troubleshooting information to help to solve the problems
you might encounter when using your SIP-T20P/SIP-T20 IP phone.
If you require additional information or assistance with your new phone, contact your
system administrator.
Why is the LCD screen blank?

Ensure that the phone is properly plugged into a functional AC outlet.

Ensure that the phone is plugged into a socket controlled by a switch that is on.

If the phone is plugged into a power strip, try plugging it directly into a wall outlet
instead.

If your SIP-T20P IP phone is powered from PoE, ensure you use a PoE-compliant
switch or hub.
Why does the phone display "Network Unavailable"?

Ensure that the Ethernet cable is plugged into the Internet port on the phone and
the Ethernet cable is not loose.

Ensure that the switch or hub in your network is operational.
Why does the phone display “No Service”?
The LCD screen prompts “No Service” message when no SIP account registers
successfully.
Why doesn’t the phone display time and date correctly?
Check if you have configured the phone to obtain the time and date from the SNTP
server automatically. If the phone fails to connect the SNTP server, you need to configure
the time and date manually.
How do I find the basic information of the phone?
Press the OK key when the phone is idle to check the basic information of the phone,
such as the IP address and firmware version. For more the basic information, refer to
Phone Status on page 13 .