As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: INOPERATIVE EMERGENCY POWER SUPPLY UNIT 12WL IN PASSENGER CABIN (1EA). REPLACED EMERGENCY POWER SUPPLY UNIT 12WL SERIAL NUMBER 4271 (AALA202111301767) IN PASSENGER CABIN (1EA) WITH EMERGENCY POWER SUPPLY UNIT 12WL SERIAL NUMBER 2940 PER AMM 33-51-38-400-001. EMERGENCY POWER SUPPLY UNIT SERIAL NUMBER 2940 WAS BAD FROM STOCK. REPLACED EMERGENCY POWER SUPPLY UNIT 12WL SERIAL NUMBER 2940 IN PASSENGER CABIN (1EA) PER AMM 33-51-38-400-001.