As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, FAULT EPSU-EMERGENCY POWER SUPPLY UNIT 12WL NOT PASS TEST IN PASSENGER CABIN (1 EA) ; REF AEROMAN N/R 2022-132476, REMOVED AND REPLACED EPSU-EMERGENCY POWER SUPPLY UNIT 12WL IN PASSENGER CABIN (1 EA) IAW 33-51-38-000-001-A AND AMM 33-51-38-400-001-A PERFORMED OPERATIONAL TEST EPSU BITE CHECK IAW AMM 33-51-00-710-001 TEST IS OK