When performing the factory reset procedure we are about to describe, it is important to keep in mind that the IP phone will lose all configuration files and phone applications. This means that it is necessary to have CallManager or CallManager Express setup so that the IP phone will be able to receive the new information (phone application and configuration) after the reset procedure is complete, otherwise it is most likely that the IP phone will not be usable until this information is loaded on to it.
This preparation also happens to be the procedure for upgrading a Cisco IP phone firmware.
Follow the steps below to successfully factory reset your Cisco 7942, 7962 IP phone:
- Unplug the power cable from the phone and then plug it back in. The phone begins its power up cycle.
- While the phone is powering up, and before the Speaker button flashes on and off, press and hold #. Continue to hold # until each line button flashes on and off in sequence in amber.
- Release # and press 123456789*0#.
You can press a key twice in a row, but if you press the keys out of sequence, the factory reset will not take place.
After you press these keys, the line buttons on the phone flash red and the phone goes through the factory reset process.
Do not power down the phone until it completes the factory reset process and the main screen appears.