As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNABLE TO TRANSMIT ON HF1. SELCAL CHECK WAS GOOD, AND ABLE TO HEAR OTHERS ON HF1, BUT CANNOT TRANSMIT. GROUNDED - YES. PERFORMED HF1 SYSTEM BITE PROCEDURE IAW B737-800 FIM 23-11-801 BITE TEST NORMAL. NO FAULTS FOUND. ABLE TO TRANSMIT AND RECEIVE NORMALLY.