As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, VTK ON CAPTAIN'S NAV DISPLAY MAP WENT AWAY. FMC PROMPT MISSING FROM BOTH CDU'S. QRH FOLLOWED AND PUT BOTH FMC BOTH ON RIGHT. DUAL FMC RESTORED. ACFT GROUNDED. PERFORMED BITE OF NR 1 FMC, NO FAULTS NOTED IAW FIM 34-60-00.