As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VTK/MAP ON NR 1 CDU UNABLE TO RESTORE NR 1 FMC SINGLE FMC OPS. DIVERSION TIME 58 MINUTES. CONFIRMED DEFECT NR 1 FMCU INOP R FMC LOGGED L FMC FAIL. CYCLED PWR TO L FMCU DISPLAY RETURNED L FMC SHOWS FAIL LAST FLT. REPLACED NR 1 FMC COMP L FMC CKS OK. GRD FUNCT CHECK SUCCESSFUL REF 34 61 02 PB401.