To restore the original factory settings, set the master power switch to OFF and wait until the light above the Network Connection stops flashing. Using a pin or straightened paper clip, depress and hold the DHCP Reset / Factory Image button while turning On the Master Power switch. Continue to depress the button until the blue ID LED flashes twice. The Factory Image should reload within a minute at most. If done correctly, the front panel indicators will turn blue and red while displaying a chasing pattern.
Please note that by doing a factory restore the unit will revert back to its original firmware.
For more information on this, please refer to page 32, section 7 of the user manual: https://anthemav.com/downloads/MDX_Manual.pdf