As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENROUTE, FMC WOULD NOT ACCEPT DIRECT ROUTING OR WOULD THE EXEC LIGHT ILLUMINATE FOR ANY FUNCTION OR INPUT. ACFT GROUNDED. FMC FAULT REVIEW SHOWS FIRST OFFICER`S FMC CDU FAULT ON THE INBOUND LEG. ACCOMPLISHED FMC OPERATIONAL TEST IAW AMM 34-61-00-710-801 AND FMC CDU COOLING VENT & SURFACE CLEANING IAW AMM 34-61-01, OPS CHECKED NORMAL. NO HISTORY LAST 30 DAYS.