As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HF 1 VOICE COMMUNICATION DISTORTED. GROUNDED - YES. HF 1 OPERATIONAL TEST REF. B737-900 AMM 23-11-00 GOOD. HF 1 SYSTEM TEST A/C TO A/C AND TALKING TO SFO-ARINC RADIO FROM SEATTLE TEST GOOD. HF GROUND VERIFICATION TEEST GOOD. NO HISTORY LAST 90 DAYS.