Watchguard DV-1 - Unit Remains Powered Off On a Reboot

SUPERVISOR/ADMINISTRATOR FUNCTIONS UPDATING DV-1 FIRMWARE
95
During the update, the system may remain powered off during an
attempt to reboot.
If the system remains powered off for more than 1 minute, press the
POWER ON key.
When the system powers on, the upgrade process continues
automatically.
NOTICE
If the system does not upgrade successfully, contact WatchGuard
Video customer service.