As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LANDING CAPTAINS VTK ON THE NAV DISPLAY. FMC PROMPT DISAPPEARED FROM CDU. SHORTLY, LATER ALL RETURNED TO NORMAL. ACFT GROUNDED. NO INFLIGHT FAULT LOGGED IN EITHER FMC. R & R LT FMC, REF AMM 34-61-02. SOFTWARE CROSS LOAD FROM RT FMC AND VERIFIED EFFECTIVE. PERFORMANCE FACTORS HAS BEEN SET AND FMC OPS TEST PASSED, REF AMM 34-61-00.