As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING GEAR EXTENTION OBSERVED MOMENTARY EICAS MESSAGE MAIN PITCH TRIM FAIL AND BACKUP PITCH TRIM FAIL. WARNING WENT OUT AFTER GEAR EXTENDED. TROUBLESHOT SYSTEM REPLACED HORIZONTAL STABILIZER UNIT. OPERATIONAL CHECK GOOD. AC RETURNED TO SERVICE. (K)