There is a front panel key sequence (on the SA boxes) to force a manual reboot (hold Vol-/Vol+ and press Info)... The box will display "-nu-", then "hold", etc.
There is another key combo to force a F/W Download (Edit: Quickly press both Select and Power WHILE the "-nu-" is being displayed)... That causes the box to display a numerical "countdown" as the firmware is erased and reloaded, (sort of like doing a BIOS Update on a PC)

-Tursiops_G.