As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ACCOMPLISHMENT OF WORK CARD 2735, FOR THE EMERGENCY LIGHTS BATTERY PACKS , NOTICED SEQUENCE OF THE 3 CEILING EMERGENCY LIGHTS OFF AT THE LT AISLE. MAINTENANCE REPLACED THE BATTERY PACK AND PERFORMED SATISFACTORY OPERATIONAL CHECK.