As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HF # 1 RECEIVES BUT DOES NOT TRANSMIT, APPEARS TO TUNE NORMALLY. GROUNDED - YES. FAULT CODE 23-21051 ACTIVE ON OMF EXISITING FAULTS. REMOVED AND REPLACED #1 HF COUPLER IAW B737-9 AMM 23-11-61. FAULT CODES NO LONGER PRESENT ON OMF. GROUND VERIFICATION SUCCESSFUL.