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 NR 1 EMERGENCY BATTERY PACK INOPERATIVE. AIRCRAFT REMOVED FROM SERVICE. REMOVED AND REPLACED THE NR 1 EMERGENCY BATTERY PACK IAW AMM 33-50-04. THE OPS CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.