Has No display - Black Screen - Not Powering on - Keypad not powering on

If there is no keypad display at all, and the LED indicators are not lit, operating power for
the system has stopped and the system is inoperative.

If the display is lit and the AC display is off, the system is operating on battery power only. 

During an AC power loss, the backlighting will turn off and the indicators will flicker slightly
to minimize deep discharge of the battery.