As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE CRUISE PHASE ON THE MIA - AMS ROUTE, THERE WERE FAULTS IN THE TRANSMISSION AND RECEPTION BY THE HF SYSTEM. THE CREW DECIDED TO RETURNED THE AIRCRAFT TO MIA STATION; AFTER THAT THE WIRING WAS CHECKED AND THE LT AND RT COUPLERS OF THE HF ANTENNAS WERE REMOVED AND INSTALLED.