As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: EMERGENCY POWER SUPPLY UNIT 10WL FAULT DISPLAYED DURING TESTING. REPLACED EMERGENCY POWER SUPPLY UNIT 10WL (AALA202306127443) AND BATTERY (AALA202306125915) PER AMM 33-51-38. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.