As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRBORNE. NEITHER HF1 OR HF2 WILL TRANSMIT. (FOR ABOUT 10 MINUTES HF1 WAS BARELY AUDIBLE-BUT CAME BACK) BOTH CAPT, F/O SIDE. HANDMIKES DO NOT TRANSMIT EITHER ON HF 1 OR 2. HF1 SAT XFER-BOTH IN HF. GROUNDED - YES. DIVERSION TIME 63 MINUTES - INITIAL TESTING, #2 HF OPS OK ON GROUND. #1 HF INOP. CYCLED POWER TO #1 HF, OPS RESTORED. PRECAUTIONARY REPLACED, #1 HF R/T REF B737-800 AMM 23-11-21/400-801. BOTH HF'S CHK OK REF AMM 23-11-00-730-801.