As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A MAINTENANCE VISIT, THE EMERGENCY LIGHTS AT ROWS 31DF THROUGH 42DF WERE FOUND TO BE INOPERATIVE. MAINTENANCE FOUND A BAD FUSE IN THE BATTERY PACK AND REPLACED M33404 NR 4 PER B777 AMM 33-50. SYSTEM OPERATION WAS NORMAL AFTER M33404WAS REPLACED.