As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN EMERG LIGHT: APPEARS FRONT EMERGENCY BATTERY IS INOP. FRONT AISLE LIGHTS OUT OVERHEAD EXIT LIGHT OUT AND BOTH SIDE ON MAIN DOOR EXIT LIGHT OUT. REMOVED AND INSTALLED OVERHAULED CUSTOMER SUPPLIED BATTERY PACK FWD REF CE560XL AMM 33-50-01