As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 FMC SCREEN WENT BLANK FOLLOWED BY A LARGE PUFF OF ELECTRICAL SMOKE. THE SCREEN DISPLAY CAME BACK ON IN 15 SECONDS AND NO FURTHER SMOKE WAS SEEN. R & R LT MCDU IAW MM 34-61-01-000-802 /MM 34-61-01-400-802. PERFORMED CDU INSTALLATION TEST IAW MM 34-61-01-400-802. OPS NORMAL.