As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, SINGLE FMC LIGHT ILLUMINATED ON CDU. F/O MAP MODE DISPLAYED WAS LOST WITH AN AMBER MAPS ANNUNCIATION COMPLETED FMC FAIL QRH AND DUAL FMC OPERATION WAS RESTORED. ACFT GROUNDED. ACCOMPLISHED FIM TASK 34-61-NO-801 FMC BITE CHECKS OK NO FAULTS LOGGED GROUND VERIFICATION TEST, OK.