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 10WL DOES NOT WORK CORRECTLY. MAINTENANCE REPLACED EMERGENCY POWER SUPPLY UNIT 10WL (AALA202303073626) AND BATTERY (AALA202303070179) PER AMM 33-51-38. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.