As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT THE AUTO-PILOT KICKED OFF IN FLIGHT AT THE TOP OF DESCENT. THE MAINTENANCE PROVIDER REMOVED THE NO2 FLIGHT GUIDANCE COMPUTER P/N 822-1108-143 S/N 3N3BX AND INSTALLED AN OVERHAULED FGC. OPERATIONAL CHECKS WERE SATISFACTORY AND THE AIRCRAFT WAS RETURNED TO SERVICE.