As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INFLIGHT THE STAB TRIM AND MACH TRIM DISCONNECTED AND WOULD RESET ONLY AFTER THE F/O TRIM DISCONNECT WAS CYCLED 4 OR 5 TIMES. POWER DOWN AIRCRAFT. OPERATIONAL CHECK OF HSTCU. OPS CHECKS GOOD IAW MM 27-41-01. RAN HORIZONTAL STABILIZER IAW MM 27-40-00 STAB TRIM AND MACH TRIM OPS CHECKS GOOD. UNABLE TO DUPLICATE DISCREPANCY.