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.