As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STAB TRIM AND MACH TRIM DISCONNECT WHEN RUNNING TRIM UP AND DOWN. (CAT II). REMOVED AND REPLACED STAB TRIM ACTUATOR. REMOVED AND REPLACED MOTOR CONTROL UNIT IAW WITH 27-42-01 AND 27-42-05. OPS CHECKS GOOD. STAB TRIM UNIT P/N 8391-3, S/N OFF 254.