A liquid crystal display device structure is provided for testing display signal lines. The display structure improves sensitivity in detecting shorts or opens in data signal lines. In the display, a first detecting line commonly connects odd-numbered data signal lines of a liquid crystal display panel, and a second detecting line commonly connects even-numbered data signal lines of the liquid crystal display panel. First and second electrostatic discharge (ESD) preventing circuits are respectively connected to the odd and even-numbered data signal lines. A first electrode line commonly connects the first ESD preventing circuits and a second electrode line commonly connects the second ESD preventing circuits. Resistances are connected in series between the common electrode lines to increase a detectable critical resistance between the two detecting lines, to thereby improve sensitivity in signal line fault detection.