As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING MTC 335000202-60045: OPERATIONAL CHECK OF THE EMERGENCY LIGHT SYSTEM, FOUND LT 3 AND RT 3 EMERGENCY BATTERY PACK INOP. REMOVED AND REPLACED EPSU BATTERY PACKS FOR LT 3 AND RT 3 REF AMM 33-51-00-820-801. OPERATIONAL TEST GOOD. NO FURTHER DEFECTS NOTED.