No Service is Displayed in Yealink T23 IP Phone
Your Yealink SIP-T23P or SIP-T23G phone LCD display shows the message No Service. There is no dial tone, and you are unable to make or receive calls.
- Yealink SIP-T23P
- Yealink SIP-T23G
In cases where the phone had been properly working for a long time and is only suddenly afflicted with these error messages, a network power cycle is often able to clear it up.
Further Network Troubleshooting
- Swap out the Ethernet cord connecting the phone to the network for a different one (to see if a faulty cord might be the issue).
- Is the phone connected to a wall jack? If so, try connecting it directly to a networking device (router or switch).
- If the phone is connected to a networking device, try plugging it into a different port on the device (to see if a faulty port is the issue).
- If accessible, review the firewall/router settings and be sure to disable the following:
You can also try setting a static IP on the phone, which has been known to help resolve these issues.
Your phone is unable to successfully register a SIP account with our services.