As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER VARIOUS INPUTS NR 2 FMC BLANKS THEN AFTER 4 SECONDS ALL LIGHTS ILLUMINATE THEN BITE TEST FOR 2 OR 3 SECONDS. THEN FMC RETURNS TO NORMAL OPS. HAPPENED ABOUT 5 TIMES IN FLIGHT. REMOVED AND REPLACED F/O MCDU PER AMM REF 34 61 01 400 802/34 61 01 000 802, OPS CHECKS GOOD.