As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HF RADIOS INOP #1 RADIO SEEMED TO RECEIVE (MAYBE INTERMITTENTLY) #2 RADIO WAS DEAD QUIET (NO STATIC/ CARRIER - NOTING)NEITHER RADIO TRANSMITTED OUT AS FAR AS I COULD TELL. GROUNDED - YES. REMOVED & REPLACED HF2 TRANSCEIVER AND PERFORMED INSTALLATION TEST GOOD, ALSO PERFORMED GOOD VOICE COMMUNICATION TEST ON BOTH HF1 & HF2 B737-900 AMM 23-11-21/401 & AMM 23-11-00-730-801.