As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH- FLIGHT 3668, ON CLIMB THE CREW NOTED THAT THE PITCH TRIM MAIN SYSTEM WAS INOPERATIVE AND NO TRIM INDICATION. THE CREW RETURNED THE AIRCRAFT TO IAH WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE NR 1 IC600 COMPUTER, PERFORMED OPERATIONAL CHECKS AND NO DEFECTS NOTED. THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.