As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 718, PHL-FCO: AT CRUISE, ENGINE PAGE DISPLAYED ON CAPTAINS NAV DISPLAY PANEL. SELECTED DMC 3 AND NR 1 DMC FAULT DISPLAYED. RESET NR 1 DMC AND PROBLEM CLEARED. RETURNED TO PHL. MAINTENANCE REPLACED THE NR 1 DMC. NO FURTHER FAULTS.