As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT, ATTEMPTED TO CONTACT SFO RADIO ON HF 1 AND HF 2 RADIOS TO NO AVAIL. IT SEEMED TO BE OVER INABILITY TO TRANSMIT OVER THE FREQUENCIES. VHF COMMUNICATIONS, ACARS, AND CDPLC ALL WORKED NORMALLY. ACFT GROUNDED. HF1 AND HF2 OPERATIONAL CHECK GOOD AMM 23-11-00-710-801. SYSTEM TEST OF HF1 AND HF2 GOOD IAW AMM 23-11-00-730-801.