As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRIOR TO TAKEOFF AS POWER WAS INCREASED, AURAL TAKEOFF WARNING SOUNDED AND PROXIMITY SENSOR ELECTRONICS UNIT LIGHT ILLUMINATED. ABORTED TAKEOFF AND RETURNED TO GATE. AIRCRAFT WAS GROUNDED. REMOVED AND REPLACED SPEED BRAKE TAKEOFF WARNING SWITCH IAW AMM 31-51-03. OPERATIONAL CHECK GOOD.