As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LLAR BACK-UP LIGHTS BATTERY PACK FUNCTIONAL CHECK FOUND THE BACK UP LIGHTS AND EXI SIGN NOT ILLUMINATED - ORIGINATED BY EMP V9054 00 ON HAECO NR 9474072, SPEC NO.B777-33-3-7024. PERFORMED BY EMP V903232, REPLACED LLAR BACK UP LIGHTS POWER SUP PLY ASSY, AND PERFORMED THE LIGHTS TEST, THE RESULT FOUND NORMAL , REF AMM 33-29-01-960-809 REV 94.