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 EMERGENCY LIGHTS AT SEATROWS 21 THRU 24 WOULD NOT TEST. LAS VEGAS FURTHER REPORT THE REMOVAL AND REPLACEMENT OF THE EMERGENCY LIGHT POWER SUPPLY BATTERY PACK AT FUSELAGE STATION 901. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED. THE AIRPLANE HAS RETURNED TO SERVICE.