As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A ROUTINE OVERNIGHT SERVICE CHECK MAINTENANCE INSPECTION LAS VEGAS MAINTENANCE REPORTED THAT THE CEILING MOUNTED EMERGENCY LIGHTS WOULD NOT TEST. THEY FURTHER REPORT THE REMOVAL AND REPLACEMENT OF BATTERY PACK(S). A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED PER AMM 33-53-00. THE AIRPLANE HAS RETURNED TO SERVICE.