As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: EMERGENCY POWER SUPPLY UNIT 13WL ON FAULT DURING BITE TEST. REMOVED AND REPLACED POWER SUPPLY UNIT ON AFT LEFT AND OPERATIONAL CHECK IS GOOD IAW AMM 33-51-78-000-001A, 33-51-38-400-001A & 33-51-00-710-001-A.