What was found
AIRCRAFT WAS GROUNDED: AFT LEFT EMERGENCY POWER SUPPLY (13WL) FAILED TEST. MAINTENANCE REPLACED EMERGENCY POWER SUPPLY UNIT PER AMM 33-51-38.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
AIRCRAFT WAS GROUNDED: AFT LEFT EMERGENCY POWER SUPPLY (13WL) FAILED TEST. MAINTENANCE REPLACED EMERGENCY POWER SUPPLY UNIT PER AMM 33-51-38.