As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: FOLLOWING REPLACEMENT OF EMERGENCY POWER SUPPLY UNIT BATTERIES PER JOB CARD 26C00033004 EMERGENCY POWER SUPPLY UNIT 13WL (AFT GALLEY CEILING) FAILS OPERATIONS TEST FOR EXTERIOR LIGHTING. REMOVED AND REPLACED EMERGENCY POWER SUPPLY UNIT 13WL PER AMM 33-51-38.