As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SAT PHONE INOP. ABLE TO CALL / TRANSMIT OUT, COULD HEAR DISPATCH BUT DISPATCH COULD NOT HEAR OUR TRANSMISSIONS- SAME RESULTS WITH SAT-1 AND SAT-2 SELECTION. PERFORMED SATPHONE LOCK-UP QRH CHECKLIST AFTER SATPHONE COMMS DISAPPEARED ALL TOGETHER. GROUNDED - YES. PERFORMED SATCOM COMMS SYSTEM TEST, ABLE TO TALK TO DISPATCH, REF B737-800 AMM 23-15-00-730-801 OPS CHECK GOOD.