As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HF #2 NOT TUNING DURING THE SYNC PORTION (KEYING MIKE W/SHORT SIDETONE) AND THUS NOT TRANSMITTING WHEN IN DATA MODE,SIDETONES INTERMITTENTLY AND CONTINUOUSLY TRYING TO SYNC BUT DOESNT. RECEIVES SELCAL NORMALLY. RECEIVES VOICE NORMALLY.VOICE TRANSMIT INOP. GROUNDED - YES. CYCLED POWER TO HF 2 W/NO SUCCESS. REMOVED AND REPLACED HF 2 COUPLER OPS CHECK OK REF B737-800 AMM 23-11-61.