As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SFO - PITCH TRIM SYSTEM REPORTED INOPERATIVE 'FROZEN' AT ALTITUDE. AIRCRAFT RETURNED TO STATION WITHOUT INCIDENT. NOTE, SYSTEM BEGAN TO OPERATE NORMALLY ON DESCENT AT MINUS 5 DEGREE CELSIUS. MAINTENANCE INSPECTED AND LUBRICATED ELEVATOR TRIM ACTUATORS. TRIM SYSTEM OPERATIONAL CHECK NORMAL. AIRCRAFT RETURNED TO SERVICE. (M)