As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DUAL FMC FAILURE WITH VTK FLAGS. BOTH FMC LEFT AND RIGHT CAME BACK ON UNDER 1 MINUTE OUTSIDE OF ETOPS AIRSPACE. GROUNDED - YES. PERFORMED FMC BITE NO CURRENT FAULTS NOTED. PERFORMED B737-900 FIM 34-61 TASK 836. RESET POWER TO FMC'S DETERMINED TO BE INTERMITTENT FAULT OK FOR SERVICE.