As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: DURING EMERGENCY POWER SUPPLY UNIT SYSTEM TEST, SYSTEM TEST FAULTED FOR EMERGENCY POWER SUPPLY UNIT 12WL. MAINTENANCE DISCONNECTED THE CONNECTOR FOR EMERGENCY POWER SUPPLY UNIT 12WL AND RE-CONNECTED IT PER AMM 33-51-38. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.