As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAIN`S FMC EXECUTE BUTTON LIGHT FLASHES WHEN SELECTING DIRECT TO A WAYPOINT WITH LIGHTS TEST SWITCH IN THE RIM POSITION. ACFT GROUNDED. REMOVED CAPTAIN`S CDU TO INSPECT FOR AIRFLOW, NO DEFECTS FOUND. REINSTALLED CDU IAW AMM REF 34-61-01. FLIGHT CREW DEMONSTRATED EXECUTE KEY FUNCTIONS NORMAL. NO HISTORY 30 DAYS, CHECKED GOOD FOR SERVICE.