As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT FMC FAIL SELECTED BOTH ON R, L FMC DID NOT COME BACK.(FMC MSG W/ VTK AND MAP ON CAPT NAV DISPLAY, NO FMC DATE ON BOTH CDU'S). OCCURRED AT CRUISE ALT FL360 2 HRS INTO FLIGHT. GROUNDED - YES. PERFORMED B737-800 FIM 34-61 TASK 36. OPS CHECK GOOD AT THIS TIME. PERFORMED FMC BITE FIM 34-61 TASK 801.