As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT UNABLE TO TRANSMIT ON SAT RADIO TO MEDLINK OR DISPATCH. INBOUND COMMUNICATION WAS WEAK. LATER IN FLIGHT POSITIVE COMM ESTABLISHED OVER BZN. GROUNDED - YES. PERFORMED CHECKING THE FAULTS MESSAGE IN EXTENDED MAINTENANCE. NO FAULTS FOUND AND PERFORMED BITE TEST SATCOM SYSTEM REF B737-9 AMM 23-15-00-740-801. PASSED.