As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OUT, THE CREW REPORTED LOOSING THE NR1 AND NR2 PITCH TRIM CHANNELS. BOTH FAIL LIGHTS ILLUMINATED. THE AUTO PILOT DISENGAGED. THE AC DIVERTED WHERE IT LANDED SAFELY, CREW DID NOT DECLARE EMERGENCY. TROUBLESHOOTING REVEALED THAT THE HORIZ STABILIZER TRIM CONTROL UNIT (HSTCU) FAILED 2 CHANNELS. HSTCU WAS REMOVED AND REPLACEDAND A SATISFACTORY OPS CHECK WAS PERFORMED IAW MM. AIRCRAFT WAS RETURNED TO SERVICE. (EA25200507339) (K)