As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HF TRANSMISSION AND RECEPTION CHECKED ON GROUND. IN AIR APPROACHING GATEWAY FIX, TRANSMISSION WAS ATTEMPTED AND BOTH FAIL FLAGS APPEARED, NO SIDETONE WAS HEARD. DESCENDING THROUGH 8500, THE HF1 RADIOS STARTED WORKING AGAIN. ACFT GROUNDED. HF 1 SYSTEM TEST DONE SUCCESSFULLY IAW AMM 23-11-00-730-801. GROUND VERIFICATION SUCESSFUL. NO HISTORY PAST 30 DAYS.