As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT GROUNDED - EMERGENCY LIGHT SIGN OVER DOOR 2L INOPERATIVE. REMOVED AND REPLACED WIRELESS EMERGENCY LIGHTING SYSTEM CONTROL UNIT BATTERY PER AMM DMC-B787-A-33-52-07-02B-520A-A, DMC-B787-A-33-51-07-02B-720A-A, OPS TEST OK. OK FOR SERVICE.