As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: FORWARD LEFT HAND EMERGENCY POWER SUPPLY UNIT 10WL FAILED SYSTEM TEST. REPLACED EMERGENCY POWER SUPPLY UNIT 10WL (AALA202305258247) AND BATTERY (AALA202305257896) PER AMM 33-51-38. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.