As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE VISIT: MAINTENANCE REPORTS FAULT EPSU-EMERGENCY POWER SUPPLY UNIT 13WL IN PASSENGER CABIN (1 EA). MAINTENANCE REMOVED AND REPLACED EPSU EMERGENCY POWER SUPPLY UNIT 13WL IN PASSENGER CABIN IAW AMM 33-51-38-400-001-A AND PERFORMED OPERATIONAL CHECK OF THE EPSU THRU BITE CHECK 33-51-00-710-001-A. BITE TEST IS OK.