As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, EN ROUTE FROM PHL TO DFW, CREW REPORTED THE CHANNEL A AUTOPILOT DROPPED OFF FOLLOWED BY THE AUTOPILOT MODE CONTROL WINDOW DISPLAYING 50,000 FEET. THE LEFT NAV THEN DROPPED OFF LINE. FLIGHT DIVERTED TO PIT AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE REMOVED AND REPLACED THE MODE CONTROL PANEL AND PERFORMED FUNCTIONAL CHECK PER R5 CARD. ALSO, REMOVED AND REPLACED FMC AND LOADED NAV DATA. OPERATIONAL CHECK NORMAL.