As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOST CPDLC CONTACT. HAD CPDLC "NO COMM" ATTEMPTED TO LOGON WITH NO RESULTS. SAW ACARS DISPLAYED "NO COMM" AND SATCOM MENU SHOWED "NOT AVAILABLE". AIRTURN BACK TO DEPARTURE. RESET FMC 1 AND FMC 2 CIRCUIT BREAKERS REF 34-63-09-05 AND CYCLED SATCOM CIRCUIT BREAKER. RAN SATCOM FANS ADJUSTMENT AND TESTED IAW AMM 23-26-01-5, TEST PASSED. SATCOM OPERATES NORMALLY.