As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: LEFT OVER WING EMERGENCY POWER SUPPLY UNIT 11WL FAILS TEST OF EMERGENCY LIGHTING. REPLACED EMERGENCY POWER SUPPLY UNIT 11WL (AALA202203220883) AND BATTERY (AALA202203227695) PER AMM 33-51-38. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.