As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HFI AND HF2 COMMUNICATION UNINTELLIGABLE ON EVERY FREQUENCY IN OCEANIC AIRSPACE. COMMUNICATION ON THESE RADIOS WAS SUCCESSFUL DEPARTING HAWAII. NO DIFFICULTIES RECEIVING SELCAL, HOWEVER VOICE COMMUNICATION WAS DIFFICULT. GROUNDED - YES. PERFORMED HF #1 & HF #2 SYSTEM TEST PASSED NO DISCREPANCY NOTED B737-9 AMM 23-11-00-730-801.