This document describes how to perform a hard factory reset on a Cisco 8831 Series IP phone, which resets all of the network and security settings of the phone.
Reset the IP Phone
There are two methods that you can use in order to reset the Cisco IP phone: a factory reset, and a hard factory reset.
In order to perform a factory reset, navigate to Apps > Admin Settings > Reset Settings. Choose one of these options in order to reset the phone to the factory default settings:
Hard Factory Reset
If the factory reset method that is described in the previous section is not possible, then a hard reset can be attempted in order to achieve similar results. However, this method resets all of the settings directly and does not provide the option to reset only the network or security settings.
Complete these steps in order to perform a hard factory reset of the phone:
1) Unplug the Ethernet cable from the back side of the phone in order to power off the phone.
Note: If the phone is powered through a power brick, then the power it off through the the power brick.
2) Press and hold the Microphone (MIC) button on the front side of the phone:
Continue to hold the MIC button and power on the phone (plug in the Ethernet cable or the power brick). When the lights that are located on the left, right, and back sides of the phone change from green to red, release the MIC button:
Press and hold the MIC button for approximately five seconds, and then release it. The lights should blink red twice.
Press and hold the MIC button. After approximately five seconds, the lights should begin to blink red continuously, which confirms the factory reset of the phone.