As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A MAINTENANCE VISIT, THE UPPER DECK FLOOR AND CEILING EMERGENCY LIGHTS WERE FOUND TO BE INOPERATIVE. MAINTENANCE FOUND PACK M7919 AT DOOR 3L CAUSING THE FAULT. MAINTENANCE REPLACED THE BATTERY PACK AT 3L DOOR. SYSTEM OPERATION WAS NORMAL AFTER THE POWER PACK WAS REPLACED.