How perform a factory reset on Crestron Flex Series phone :
1. Power cycle the phone by disconnecting and reconnecting the Ethernet cable to the PoE switch.
2. When the phone powers on and the LEDs flash green, press and hold the Volume+ and Mute buttons together for at least 10 seconds.
3. When prompted, confirm the factory reset. Press Volume- and Volume+ to select the option, and press Mute for OK.
4. The phone will reboot.