Following are instructions for performing a factory reset for models of Cisco VoIP phones that are commonly used on the U-M campuses. The general approach is to unplug the phone from power (either a powered Ethernet cable or AC power supply), plug the phone back into power while holding down a button, and then pressing a series of keys. Several models have an easier approach where a full reset is available from the phone menu's commands. Using either approach, the phone goes into a series of reloading steps that might take 1-5 minutes. At the end, the phone is restored to factory settings and any stored data is removed.
Power instructions for all phones:
- The instructions below assume starting from a state where the phone is completely unplugged.
- Typically VoIP phones are powered by a powered Ethernet jack.
- Most phones will have three Ethernet jacks on the back of the unit; they are labeled but sometimes hard to read. They usually appear in the following order right to left but some phones may vary:
- "Aux". This jack is sometimes used for external equipment. Do not use this jack to power the phone.
- "10/100 SW" or "10/100/1000 SW" or an icon showing interconnected devices. This is the jack that should be used to power the phone.
- "10/100 PC" or "10/100/1000 PC". This jack is used when setting up the phone to pass through to a connected computer. Do not use this jack to power the phone.
- Note: A VoIP phone doesn't have to be plugged into an activated Power over Ethernet (PoE) jack to perform a reset. Most phones can also perform the factory reset if plugged in using a Cisco DC power supply, or using an Ethernet power injector that provides power over Ethernet via an Ethernet cable but without live data service.
These instructions will be updated to accommodate new findings and variations. If you have a problem or have a useful hint or discovery, please send email to [email protected].