Yealink SIP-T48S Rebooting, Updating Firmware/configuration, Factory Reset

If your phone is malfunctioning or requires updates you or your phone system administrator may want to perform one of the following:

Rebooting - this will bring the phone back to the its last configured state. It is also required sometimes when TeleConsole settings have been updated such as after modifying TeleConsole BLF settings.

Updating configuration - settings or configuration changes made by Telebroad or your system administrator are applied to the phone when you trigger a configuration update. Depending on the updated settings this may or may not require you to restart your phone.

Updating firmware  - firmware is the software that loads when the phone is started and controls its functionality. Updating it to a newer version, when one is released, may resolve or improve phone performance issues. 

Factory reset - this erases the current configuration and apply the original configuration the phone was shipped with from the factory.  It is possible to erase just the phone configuration, just the the user customized data, or both. You may do this if you forgot your phone's admin password

Rebooting Your Phone

Rebooting your phone is usually a safe and easy method to resolve functionality issues. However, you may want to consult your phone system administrator first to make sure the issues are not related to network problems or other external causes. 

To reboot your phone do one of the following:

  • On the phone, navigate to Menu>Basic>Reboot.

  • Long press Cancel () on the keypad when the phone is idle.

  • Access the phone via the web user interface as explained here.

    Click on Settings>Upgrade.

    Click Reboot.

  • Press or select OK when prompted to confirm that you want to reboot the phone.

Updating Configuration

Changes in the system or network of your office may cause problems with the functionality of your phone. To restore compatibility or simply to apply new settings for improved workflow, your system administrator may ask you to update the phone's configuration after he has prepared the relevant configuration file. 

When you trigger the configuration update the new configuration file is downloaded from a provisioning server to the phone's flash memory and the update process is completed automatically. 

To update the configuration of your phone:

  • Do one of the following:

    • Navigate to Menu>Basic>Update Configuration.

    • Long press   (redial) when the phone is idle.

  • Select OK when prompted by a "Provision now" message to approve the update.

Upgrading the Firmware

Firmware files can be downloaded from the Yealink support portal. The downloaded file should be stored on a computer or network location that can be accessed by the web user interface. 

You can check the current firmware version installed on the base or a handset to see if an update is indeed required. 

To check the firmware version via phone user interface: 

  • Press    or tap  >Status.

  • The screen displays status information of the phone in various tabs. The firmware version is under the General tab along with the IPv4 or IPv6 status and MAC address. 

    You may need to provide information from this or the other tabs, besides the firmware version, to your phone system administrator for additional phone support or maintenance.

To check the firmware version via  the web user interface:


  • Access the phone via the web user interface as explained here.

  • The firmware version is the first item found under the Status>Status path on the first page of the web user interface.

    Other information is show here including IPv4 or IPv6 status, network configuration, and account status. You may need to provide some of this information , besides the firmware version, to your phone system administrator for additional phone support or maintenance.

To upgrade the firmware via the web user interface: 

  • Click on Settings>Upgrade.

  • Click Browse to locate the required firmware file on your local system.

  • Click Upgrade to upgrade the firmware.

    The browser pops up the dialog box “Firmware of the SIP Phone will be updated. It will take 5 minutes to complete. Please don't power off!”.

  • Click OK to confirm upgrading.

Factory Reset

This is only recommended after you have tried the other troubleshooting suggestions. Since two of the options here will delete all your personal configuration settings, it is advisable to have your phone system administrator backup your personalized settings before proceeding.

To perform a factory reset from your phone:

  • Tap >Advanced.

    If prompted for password enter the default password ("admin") or the current phone's admin password.

    Select Reset Config>Reset to Factory.

  • Tap the gray box of the Reset Option field, and then select the desired reset option from the pull-down list:

    • Full Reset - all configurations and the user data on the phone will be reset.

    • Config Reset - all configurations (e.g., account, call history) set on the phone will be

    • Userdata Reset - all custom data (e.g., ring tone) set on the phone will be reset.

  • Tap the Reset key.

    The touch screen prompts the following warning:

  • Tap OK.

    The phone begins resetting. The reseting process may take a few minutes. Do not power off until the phone has started up successfully.

  • When the resetting is done the touch screen prompts “Welcome Initializing…Please wait”.

If you forgot or don't know the admin password of the phone you can contact your phone system administrator and ask him to change the phone's settings so it does not require one when you long press the redial key (the specific configuration file setting is “features.factory_pwd_enable=0” )Update your phone's configuration if your administrator asks you to. You should now be able to reset your phone without being prompted for a password. After the reset, the default password (admin) should work. 

To perform factory reset of the phone via the web user interface:

  • Access the web user interface as explained here.

    You can only perform a full reset via the web user interface!

  • Click Settings>Upgrade.

  • Click Reset to Factory Settings in the Reset to Factory field.

  • The web user interface prompts “Do you want to reset to factory?”.

  • Click OK to confirm.

  • The screen prompts “Welcome Initializing…Please wait”.

    The phone will be reset to factory successfully after startup.

    The process may take a few minutes. Do not power off until the phone starts up successfully.

Did you find it helpful? Yes No

Send feedback
Sorry we couldn't be helpful. Help us improve this article with your feedback.