As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 HF INCOMING COMMS GARBLED AND UNREADABLE. OUTGOING TRANSMISSIONS WORK FINE. TRIED TUNING & DETUNING SEVERAL FREQUENCIES WITH NO CHANGE. PREFLIGHT HF NR 1 CHECK HAD ALL COMMS NORMAL. HF NR 2 WORKS PERFECTLY. ACFT GROUNDED. REMOVED AND INSTALLED NR 1 HF TRANSCEIVER IAW MM 23-11-21. SYSTEM OPS CHECKED NORMAL. RADIO RECEPTION WAS 5 BY 5.