We have conducted extensive investigations on abnormal horizontal line of touchscreen. Without changing a‐Si gate driving circuit, we obtained a novel method that could handle this problem. The capacitance of gate driving circuit is discharging during the touch period, in that case abnormal output of gate is produced which makes the horizontal dim line happened. In this paper, we have succeeded in modulating the timing of our gate driver circuit during touch period to address the abnormal horizontal dim lines.