What was found
DURING HEAVY MAINTENACE: FAULT EPSU EMERGENCY POWER SUPPLY UNIT BATTERY 10WL, 11WL,12WL, 13WL IN PASSENGER CABIN (4EA); REF: ARM W/O 2022 175/1 NR 2022-420207 REMOVED AND REPLACED EPSU EMERGENCY POWER SUPPLY UNIT BATTERY 10WL, 11WL, 12WL, 13WL IN PASSENGER CABIN (4EA) INAW AMM 33-51-38-000-002-A AND AMM 33-51-38-400-002-A AND PERFORMED OPERATIONAL TEST IAW AMM 33-51-00-710-001 AND TEST IS OK.