As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT EXPERIENCED INTERMITTENT -FLAPS PRIMARY+ AND -FLAPS DRIVE+ MESSAGES IN-FLIGHT SOON AFTER TAKE-OFF. FLIGHT CREW ELECTED TO DUMP FUEL AND RETURN TO FIELD. THE L1 LEADING EDGE FLAP DRIVE UNIT POSITION SWITCH ASSEMBLY WAS REPLACED WITH AN IMPROVED P/N SWITCH. THE OLD SWITCH HAS BEEN KNOWN TO CAUSE NUISANCE EICAS MESSAGES.