As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING MAINTENANCE INSPECTION FOUND THE EMERGENCY POWER SUPPLY UNIT NR 2 NEEDS TO BE REPLACED. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE EPSU NR 2 S/N 14911 EMERGENCY BATTERY POWER SUPPLY AND BATTERY HOLDER ASSEMBLY IAW AEA WC 33-700-19. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.