As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DISCOVERED BLUE DYE WASHOUT FROM FCU INDICATION OF INTERNAL MALFUNCTION OF COMPONENT. BLUE DYE FOUND IN ARE OF MATING SURFACE OF FCU AND FUEL PUMP, INDICATIVE OF INTERNAL SEAL FAILURE. NO IN-FLIGHT INDICATIONS NOTED. FOUND DURING A PREFLIGHT INSPECTION. AIRCRAFT GROUNDED. FCU AND FUEL PUMP SUBSEQUENTLY CHANGED. OPERATIONS NORMAL.