As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT CDU BLANKED OUT FOR A MOMENT EN ROUTE. ABOUT 5 SECONDS IT WENT THROUGH A SERIES OF BIT TEST THEN CAME BACK TO A NORMAL SCREEN. CHECKED FMC INFLIGHT FAULT LEFT FMC CDU FAULTED. PERFORMED FIM 34 61 TASK 804 FAULT RESET CDU TEST GOOD REF FIM 34 61 TASK 804.