As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - CREW REPORTED ALTERNATE STAB TRIM FAILED AND AUTO PILOT WOULD NOT HOLD ALTITUDE. EMERGENCY DECLARED FLIGHT RETURNED DFW LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED ALTERNATE STAB TRIM MOTOR. SYSTEM GROUND CHECK NORMAL OPERATION.