As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FIRST FLIGHT OF THE DAY TEST FOR EMER LIGHT ON PERFORMED & GOT NO MSG & DID NOT GET ANY OF THE INDICATIONS OF ANY LIGHTS IN CABIN. DID GET THE EMER LLS OFF CAUTION MSG. PERFORMED THE SAME TEST FROM THE FLIGHT ATTENDANT`S PANEL & DID NOT SEE ANY INDICATION. R & R ALL 4 BATTERY PACKS IAW AMM 33-51-04-400-801. OPERATIONS CHECKED GOOD ON ALL BATTERY PACKS.