What was found
THE UP TRAVEL SWITCH ON THE RT FLAP FAILED TO TRIP UPON FLAP RETRACTION. THIS CAUSED THE FLAP MOTOR TO CONTINUE TO RUN ALTHOUGH THE FLAP WAS ALREADY FULLY RETRACTED. THE MOTOR OVERHEATED AND STARTED GENERATING SMOKE. THE ACFT WAS ON THE GROUND, TAXIING FOR TAKEOFF WHEN THIS WAS DISCOVERED. THE ACFT RETURNED TO THE RAMP. UPON INSPECTION BY MX STAFF IT WAS DISCOVERED THAT THE ARM ON THE FLAP UP TRAVEL SWITCH WAS BENT (CAUSE UNKNOWN.) THIS PREVENTED THE SWITCH FROM CLOSING. A CAREFUL EXAMINATION OF THE AREA COULD NOT REVEAL WHAT CAUSED THE ARM TO BEND. SPECULATION IS THAT PERHAPS IT WAS RELATED TO ICE OR FOD DEBRIS.