As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 779, EXIT LIGHT LEFT OVERWING NOT WORKING ( EXIT MARKING SIGNS/BULBS (NO PAX) ); PERFORMED GROUND SCAN OF EMERGENCY LIGHTING SYSTEM AND FOUND EPSU BATTERY PACK EMERGENCY ROW LEFT SIDE PERFORMED BATTERY PACK TEST ON EPSU AND FAIL LIGHT ILLUMINATED. R & R BATT EMERGENCY LIGHT REF AMM 33-51-38 AND SYS CHECK PERFORMED ALL CHECKS NORMAL MX-4 UPDATED DISPATCH NUMBER 00905.