What was found
ON TAKE OFF ROLL A/C ON CENTERLINE. F/O TAKEOFF. A/C VEERED LEFT. F/O APPLIED FULL RIGHT RUDDER BUT A/C CONTINUED TO VEER LEFT. CAPTAIN TOOK A/C APPLIED RT BRAKE TO IDLE POWER TO BRING A/C TO CENTERLINE. AFTER REJECT BOTH CAPT AND FO TESTED RUDDER STEERING ON RUNWAY A/C STEERED NORMALLY. RETURNED TO GATE FOR TROUBLESHOOTING. A/C TURNED 20 DEG-30 DEG TO LEFT OF CENTERLINE, LESS THAN 50KTS PRIOR TO REJECT. REMOVED AND INSTALLED NLG STEERING CONTROL V/V PER AMM 32-52-03-4. NLG STEERING OPS CHK GOOD.