A line-on-glass type liquid crystal display device, which includes a gate drive integrated circuit mounted on a liquid crystal display panel for supplying a gate signal to the liquid crystal display panel, and a data drive integrated circuit for supplying a data voltage to the liquid crystal display panel. Further, the data drive integrated circuit includes an output circuit having effective output channels to which the data voltage is supplied and dummy output channels to which at least any one of the data voltage and a common voltage is supplied. Also included is a channel selecting part for selectively supplying any one of the data voltage and the common voltage to at least anyone of the dummy output channels.