As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 MCDU DID NOT HAVE SAT PROMPT. ACCOMPLISHED QRH FOR SAT LOCKUP. SAT WAS ON NR 2 MCDU BUT DIDN'T RETURN ON NR 1 MCDU FOR APPROXIMATELY 1 HOUR. ACFT GROUNDED. VERIFY SATCOM OPS NORMAL WITH PROMPT IAW AMM 23-15-00. AS A RECAUTION, REMOVED AND REPLACED IRIDIUM TRANSCEIVER IAW AMM 23-15-00. SATCOM COMMUNICATION OPS TEST NORMAL IAW AMM 23-15-00.