As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STAB TRIM NR 1 + 2 AND MACH TRIM DISENGAGED MULTIPLE TIMES DURING FLT WITH AUTO-PILOT NOT NOT ENGAGED WOULD RESET MOMENTARILY ONCE AUTO PILOT WAS ENGAGED ONLY STAB TRIM CHANNEL 1 STATUS MESSAGE APPEARED 3 TIMES. R/R STAB TRIM ACTUATOR IAW AMM 27-42-01. OP/C GOOD. REMOVED AND REPLACED MCU IAW AMM 27-42-05.