As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) IN POSITION ON RWY FOR DEPARTURE. THRUST LEVERS ADVANCED TO TAKEOFF THRUST FOLLOWED BY THE TAKEOFF WARNING HORN. THRUST RETARTED TO IDLE. FLAPS RESELECTED UP THEN BACK TO FLAPS 15, STAB TRIM MOVED TO ZERO THEN BACK TO TAKEOFF POSITION, SPD BRAKES DEPLOYED AND STOWED. RE-ATTEMPED TO SET THRUST TO TAKEOFF AND HORN SOUNDED AGAIN. RETURNED TO GATE FOR MAINT FOLLOW UP. SYS INSP CARRIED OUT, FOUND UPPER STABILIZER TAKEOFF WARNING SWITCH (S532) AT FAULT.