Problem: Cisco desk phone will not register.


Solution: First unplug the ethernet cable from the back and plug back in. This is a simple reset. If this does not work try a factory reset.


This will work on most models of the Cisco desk phones we have.


Factory Reset. Follow these steps:


  1. Unplug the ethernet cable from the back of the phone.
  2. Hold the hash (#) button down as you plug the cable back in. What for the line buttons to flash on and off orange.
  3. Release the hash (#) key and type all the keys in this sequence: 123456789*0#


After enter the key sequence the display should show it is updating firmware. This process can take several minutes. In most cases (after 10 or 15 minutes) the phone will be back to normal.