As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HF RADIO - TUNING PROBLEM. NR 2 HF RADIO TUNING PROBLEM. NR 2 HF RADIO INOP. NO FAULTS ON MAT OR AHM, HF SYSTEM TEST OK, RT HF DOES NOT TUNE, TRIED FROM CAPT & F/O'S PANEL. REPLACED TRANSCEIVER REF MM, NO HELP. SUSPECT COUPLER. REPLACED NR 2 HF COUPLER. OPS CHECK GOOD REF STEP G.