As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB THE CREW REPORTED THE NR 2 TRANSPONDER. THE ACFT RETURNED TO DEPARTURE WHERE IT LANDED WITHOUT INCIDENT. MX R & R THE INTEGRATED COMM /TRANSPONDER UNIT, OPERATIONALLY TESTED WITH NO DEFECTS, AND THE ACFT WAS APPROVED FOR RETURN TO SERVICE.