As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT AND RIGHT FMCS INTERMITTENTLY LOCKING UP. KEYS ON MCDU PAD DON'T WORK, FMC PROMPT AND ICON ON THE L1 ISN'T DISPLAYED AND AMBER VTK WARNING SHOWS INTERMITTENTLY ON CAPTAIN`S ND. ACFT GROUNDED. REMOVED & REPLACED THE NR 1 FMCS IAW AMM 34-61-02. PERFORMED FMC SOFTWARE CROSSLOAD, PERFORMANCE FACTORS ADJUSTMENT & OPS TESTED NORMAL IAW AMM 34-61-00. VERIFIED AIPC 34-61-02 FOR FMCS & SOFTWARE P/N.