As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRIMARY STAB TRIM FAILED DURING CLIMB. ALTERNATE TRIM OPERATED NORMAL. RETURNED TO CVG. YOKE AND SUITCASE SWITCHES BOTH WERE INOP. TRIM FAILED AT 2 UNITS. CHECKED POWER IN AND OUT OF TRIM RELAYS. CHECKED POWER AT PRIMARY TRIM MOTOR AND BRAKE WITH METER AND TEST LIGHT. ALL CKS OK. REPLACED PRIMARY STAB TRIM MOTOR AS PRECAUTIONARY. ALL CKS GOOD.