Mike's PBX Cookbook

Resetting Cisco phones

If you're having trouble getting a Cisco phone to register, it may need to be reset to factory defaults.

When a Cisco phone is factory reset, the following settings are erased or defaulted:

Information Erased:
  • ITL (Initial Trust List) file
  • CTL (Certificate Trust List) file
  • LSC (Locally Significant Certificate) file
  • Phone application
  • Call History
Reset to Default:
  • All user settings:
    - ring tone, screen brightness, volume, etc...

  • Network settings:
    - DHCP is enabled by default

Certificate files authenticate and decrypt the (AES) encrypted TFTP configuration files issued during registration.
Therefore, an invalid ITL (and/or CTL) file will prevent a phone from being re-deployed on a different system.

Deleting the ITL file:

  1. Goto Settings ➤ Security Configuration ➤ Trust List
  2. In the Trust List menu, unlock the phone by pressing **#, an open padlock icon is displayed.
  3. Select the ITL file to delete, press Unlock softkey, press more, press Erase
    The phone should indicate that it's deleting the ITL file, and reboot.

If the phone will still not register, reset it to factory defaults.

Generic factory reset procedure:

  1. Press and hold #, power cycle the phone
  2. When an LED starts to flash, release #, and enter:

    • Soft Reset (delete files): 123456789*0#
    • Hard Reset (format flash): 3491672850*#

    The phone will display Upgrading and erase its configuration.
    If a Soft reset doesn't work, try a Hard reset!

Other codes:

Reset Specific models:

Factory reset procedures for the following models:

Cisco 6901 phone Factory Reset:

Cisco 6901
  1. Unplug the power cable from the phone, then plug it back in. The phone begins its power-up cycle.
  2. While the phone is powering up, press and hold # button until the Line LED turns green.
  3. Release the # button and press 123456789*0#
    The line button LED turns red. The phone reboots when it is finished.

Cisco 7841 phone Factory Reset:

Cisco 7841
  1. Unplug the phone:
    • If using PoE, unplug the LAN cable.
    • If using a power brick, unplug it.
  2. Wait 5 seconds.
  3. Press and hold # and plug the phone back in.
  4. When the Mute button light and handset strip light both turn off (all other lights stay green), press 123456789*0# in sequence.
    When you press 1, the lights on the line buttons turn red. The light on the Select button flashes when a button is pressed.
    After you press these buttons, the phone goes through the factory reset process.
    If you press the buttons out of sequence, the phone powers on normally

Alternative method:

  1. Power cycle the phone, and let it boot up normally.
  2. Once the boot up is complete, press the Settings button.
  3. Hit the unlock combination **# and a you'll see an Erase softkey appear.
  4. Password is: Cisco.

Perform Factory Reset from Phone Menu:

  1. Press Applications
  2. Select Device administration ➤ Factory reset
  3. Scroll to Admin Settings ➤ Reset Settings, and select All
  4. To restore phone configuration or settings to factory default, press OK

Cisco 7940 / 7960 phone Factory Reset:

Cisco 7490
  1. Unplug the power cable from the phone, and then plug in the cable again: the phone begins its power up cycle.
  2. Immediately press and hold # until the Headset/Mute and Speaker buttons flash in sequence: release #

    The Headset/Mute & Speaker buttons flash in sequence indicating you may enter the reset key sequence.

  3. Press 123456789*0# within 60 seconds after the Headset, Mute, and Speaker buttons begin to flash.

    • If you repeat a key within the sequence, eg: 1223456789*0#, it is still accepted and the phone resets.
    • If you do not complete this key sequence, after 60 seconds the phone starts normally and does not reset.
    • If you enter an invalid key sequence, the buttons no longer flash, and the phone starts normally and does not reset.
    • If you enter this key sequence correctly, the phone displays this prompt: Keep network cfg? 1 = yes 2 = no

  4. To maintain the current network configuration settings for the phone when the phone resets, press 1.
    To reset the network configuration settings when the phone resets, press 2.

    If you press another key, or do not respond to this prompt within 60 seconds, the phone starts normally and does not reset. Otherwise, the phone goes through the factory reset process.

Cisco 7941 / 7961 phone Factory Reset:

Cisco 7941
  1. Unplug the power cable from the phone, and then plug in the cable again: the phone begins its power up cycle.
  2. Immediately press and hold # until the Headset/Mute and Speaker buttons flash in sequence: release #

    The line buttons flash in sequence indicating you may enter the reset key sequence.

  3. Press 123456789*0# within 60 seconds after the Headset, Mute, and Speaker buttons begin to flash.

    • If you repeat a key within the sequence, eg: 1223456789*0#, the sequence is still accepted and the phone resets.
    • If you do not complete this key sequence, after 60 seconds the phone starts normally and does not reset.
    • If you enter an invalid key sequence, the buttons no longer flash, and the phone starts normally and does not reset.
    • If you enter this key sequence correctly, the phone displays: Upgrading and erases its configuration.

8841/8851 series desk IP phone

Cisco 8841

A hard factory reset resets all of the parameters of the phone including network and security settings. This is sometimes necessary for troubleshooting or resolving phone issues.

  1. Unplug the Ethernet cable from the phone. Wait 5 seconds. Press and hold #
  2. Plug in the Ethernet cable. The headset and speaker buttons will light up.

  3. Release # and enter the following: 123456789*0#
    Note: The headset light will turn off after you press 1.

  4. If the sequence is correctly entered, the Mute button will light up, indicating the phone is performing a factory reset.
    If the Mute button does not light up, repeat these steps.
  5. The main phone screen will appear. The phone resets.

Factory Reset from Phone Menu:

8831 series conference IP phone

The 8831 Series IP phone is a conference phone with a soft keypad, a microphone and a speaker. Cisco 8831

Soft factory reset:

  1. Click Apps ➤ Admin Settings ➤ Reset Settings
  2. Choose one option to reset the phone: All, Network, or Security.

Hard factory reset:

A hard factory reset restores all settings to factory default, including network and security settings.

  1. Unplug the Ethernet cable from the phone. Press and hold the microphone button.

    Cisco 8831

  2. Holding the microphone button, power on the phone by plugging in the Ethernet cable. There are lights on the left, right and back sides of the phone. When they change from green to red, release the microphone button.

    Cisco 8831

  3. Press and hold the microphone button for about 5 seconds then release it. The lights will blink red twice.
  4. Press and hold the microphone button. After about 5 seconds, the links will blink red continuously, indicating that the hard reset is complete.