As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EFD - DURING MAINTENANCE INSPECTION, THE FORWARD EMERGENCY AISLE PATH LIGHTS WERE FOUND TO BE INOPERATIVE. MAINTENANCE REMOVED AND REPLACED THE AFFECTED BATTERY PACK IAW ATR24-500 JIC 33-51-21, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE (M)