As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEVEL FL380 IN CRUISE. RIGHT FMC MASTER. LEFT FMC P/RST LIGHT ILLUMINATED FOLLOWED BY LT MAP DISPLAY DATA REMOVED AND "VTK" ILLUMINATED ON NAV DISPLAY. LEFT CDU MENU DISPLAY WITH NO FMC ON MENU. AFTER 2 MIN ALL DATA AND INDICATIONS REBUILT ITSELF TO NORMAL DISPLAYS. ACFT GROUNDED. RESET BOTH FMC SYSTEMS AND TESTS NORMAL IAW FIM 34-61, TASK 807. ETOPS SIGNIFICANT SYS, GROUND VERIFICATION SUCCESSFUL.