As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: FAILED OPERATIONS OF EMERGENCY LIGHT SYSTEM WITH FAULT 335100 BATTERY/EMERGENCY POWER SUPPLY UNIT (10WL) FORWARD LEFT. REMOVED AND REPLACED BATTERY EMERGENCY POWER SUPPLY UNIT ON POSITION (10W) (AALA202110193030) AND (12W).