As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TAKEOFF WARNING HORN SOUNDED WHEN THROTTLES WERE ADVANCED FOR TAKEOFF. CYCLED FLAPS AND SPEED BRAKES, NO HELP. ABORTED TAKEOFF AT 10 TO 20 KNOTS AND RETURNED TO GATE. REPLACED TAKEOFF WARNING SWITCH. OPERATIONAL CHECK OK AND AIRCRAFT RETURNED TO SERVICE.