As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE: DONT PASS OPERATIONAL TEST BATTERY EPSU MID LH 15WL AT PASSENGER CABIN; REMOVED AND REPLACED BATTERY EPSU MID LH 15WL AT PASSENGER CABIN IAW AMM 25-23-41-000-001-A AND AMM 33-51-38-000-002-A AND AMM 25-23-41-400-001-A. PERFORMED OPERATIONAL TEST. TEST IS OK.