ben i don't know fds hardware but yes one thing is the backlighting system of the panels (backlighting is available when aircraft is energized and dimmable thru INTEG LT knob on the pedestal) and one separate thing are the green leds of the buttons of the ecam control panel lighting up when button is pressed and corresponding ecam page showed on SD.
pls note that EMERG CANC button is ALWAYS lit in red as the aircraft is energized.
regards
fil