Explanation/Reference:
Explanation: Resetting the EX90 to factory settings:
1. Unplug the power cable.
2. Replug the power cable.
3. Press and hold the power button immediately when the green LED in the bottom left corner lights up.
Hold until the LED turns off and on again after approximately 10 seconds.
4. Release the power button, and press it twice within 2 seconds.
The TANDBERG EX90 is now reset to factory defaults.
A factory reset can also be performed by executing a single API command.
Log into the TANDBERG EX90 as admin using SSH (Secure Shell):
1. Execute the API command: xCommand systemunit FactoryReset Confirm: Yes
2. The system will now reboot
The procedure will reset or delete:
All passwords to factory default

All configurations to factory default, including SIP and H.323 settings

Local phonebook

All logs

DHCP-information

The procedure will not delete software release - and option keys.
Reference: http://www.cisco.com/c/en/us/support/docs/collaboration-endpoints/telepresence-system- ex90/112501-pqa-112501-00.html