As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER T/O ON FLAP & SLAT RETRACTION HAD SLAT DISAGREE LIGHT ILLUMINATE. FOLLOWED RED TAB TO SLAT EXTEND LIGHT EXT. RETURN TO AIRPORT. DUMPED FUEL. INSPECTED ALL 6 SENSORS & TARGETS. PERFORMED BITE TEST ON SENSOR AT PROX BOX. ALL TESTS GOOD. DID SHAKE TEST ON ALL SLATS AT SENSORS, NO DISAGREE LIGHT SHOWING. CYCLED SLATS MANY TIMES & COULD NOT REPRODUCE MALFUNCTION. R&R PROX SWITCH CONTROL BOX FOR PRECAUTION & REPEATED ALL ABOVE TESTS. ALL CHECK NORMAL. NO HISTORY SHOWN. ALL MX DONE IAW MM 27-80-01-6 2 AND 27-84-01-2.