As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT ALTITUDE ALL 3 TRIM WHEELS BECAME VERY RIGID AND DIFFICULT TO ROTATE. 'AP HOLDING ND' AND 'MISTRIM' ANNUNCIATOR ILLUMINATED. DIVERTED TO SMF. ON DESCENT TRIM WHEELS FREED UP. MAINTENANCE INSPECTED ELEVATOR, AILERON AND RUDDER TRIM ACTUATORS FOR MOISTURE. NON FOUND. LUBED ACTUATORS AND A SUCCESSFUL OPERATIONAL CHECK FLIGHT WAS PERFORMED. AIRCRAFT WAS RETURNED TO SERVICE.