As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND CABIN OVERDOOR L4 EMERGENCY LIGHT POWER SUPPLY LOW BATTERY (M33407) REFER HAECO NON-ROUTINE NO.9491784 - ORIGINATED BY EMP V905400 SPEC NO.B777-33-3-7021 PERFORMED BY EMP V905400 REPLACED CABIN OVERDOOR L4 EMERGENCY LIGHT BATTERY AND PERFORMED THE INSTALLATION TEST,THE RESULT FOUND NORMAL REF AMM 33-51-06-960-802 REV 95(ON P/N ADD717-01-10 0,S/N:286588;OFF P/N:ADD717-01-100,S/N:77097) IDT BY EMP V905459