As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNABLE TO TRANSMIT / RECEIVE ON HF 2. REPLACED NUMBER TWO HF TRANSCEIVER REF ETOPS AMM 23 11 21 OPS CK NORMAL. PERFORMED HF COMM SYS TEST REF ETOPS AMM 23 11 00 OPS CK NORMAL. FLIGHT CREW TO COMFIRM NUMBER TWO HF RADIO NORMAL IN VOICE. VERIFICATION FLT SATISFACTORY. DUE TO HISTORY ENGINEERING REQS REPLACEMENT HF COUPLER. COUPLER REPLACED.