As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 HF WE LOST THE ABILITY TO TRANSMIT VOICE. DATA AND INCOMING RADIO CALLS CONTINUED TO WORK BUT WE COULD NOT RESPOND BACK FROM EITHER COM PANEL. ACFT GROUNDED. LRU STATUS PASSED, OPS CHECKED NR 1 HF ON BOTH COM PANELS ON PRIMARY AND BACK-UP FREQUENCY PROVIDED, REF AMM 23-11-00-730-801. GROUND VERIFICATION TEST SATISFACTORY.