As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THAT THEY RECEIVED A PITCH TRIM MAIN INOPERATIVE MSG IN FLIGHT. THE CREW RETURNED TO FIELD & LANDED WITHOUT INCIDENT. MX REPLACED THE AUTO PILOT DISCONNECT SWITCH. OPERATIONAL CHECKS WERE GOOD WITH NO FURTHER DEFECTS NOTED.