As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 2780 - DURING PREFLIGHT INSPECTION THE CEILING EMERGENCY LIGHT AT THE PASSENGER DOOR DID NOT ILLUMINATE WHEN TESTED. MAINTENANCE REMOVED AND REPLACED THE NR 4 EMERGENCY LIGHT BATTERY PACK, OPERATIONALLY TESTED THE LIGHTING SYSTEM AND CLEARED THE DISCREPANCY.