As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SATCOM SYSTEM SATCOM SYSTEM FAILS OR NO BUSS ACTIVITY. STATUS MESSAGE 01- ACTIVE CRUISE HARD; SATELLITE DATA UNIT (LEFT) HAS NO OUTPUT ON ANY BUSS. MSG-2368801 ACTIVE ER HARD. RESET CB'S TO TEST SATCOM UNIT. NO SATCOM LEGEND INDICATED ON FMC. REPLACED SDU.