As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LANDING BOTH MCDU'S DISPLAYED THE MENU PAGE WITHOUT AN FMC PROMPT. FMC PROMPT LATER RETURNED WITH ALL DATA LOST. ACFT GROUNDED. FMC BITE LT & RT FAULTED LT FMC, WHILE ATTEMPTING OPS CHECK, LT FMC FAILED AGAIN. R & R LT FMC COMPUTER REF AMM 34-61-02. ALL SOFTWARE CROSSLOADED FROM RT FMC & VERIFIED EFFECTIVE. FMC OPS TEST PASSED.