As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: EMERGENCY POWER SUPPLY UNIT FORWARD LEFT FAULT AND ARMED LEFT FAULT DURING EMERGENCY LIGHT BITE TEST. REMOVED AND REPLACED EMERGENCY POWER SUPPLY UNITS 4401 AND 4591 (AALA202110110024), PERFORMED OPERATIONS CHECK, GOOD PER AMM 33-51-38-869-002 AND AMM 33-51-00-710-001-A.