As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE WORKING A LIGHTING ISSUE, FME DISCOVERED CENTER EMERGENCY LIGHTING ON CEILING EXIT LIGHT DOES NOT ILLUMINATE W/ EMERGENCY LIGHTS ON. REMOVED BATTERY PACK & REINSTALLED IAW B747-400 AMM 33-51-00, REPLACED BATTERY POWER SUPPLY FUSES IAW AMM 33-51-00 & TESTED EMERGENCY LIGHTS AND SIGNS, OK IAW AMM 33-51-00, SIGN ILLUMINATES.