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 12WL DOES NOT WORK CORRECTLY. MAINTENANCE REPLACED EMERGENCY POWER SUPPLY UNIT 12WL (AALA202303029869) AND BATTERY (AALA202303027030) PER AMM 33-51-38. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.