Display substrate and apparatus and method for testing display panel having the same

A method for testing a display panel including a plurality of pixels, a plurality of source lines, and a plurality of gate lines, the method comprising:

• applying a gate test signal and a source test signal to the gate and source lines, respectively, to firstly detect defects of the display panel;
• and
• applying a first test signal and a second test signal to the first and second test parts, respectively, to secondly detect defects of the display panel,
• the display panel further including:
• a first test part electrically connected to the source lines through a first static dissipative part,
• a second test part electrically connected to the gate lines through a second static dissipative part,
• a storage voltage line receiving a common voltage, and
• a static discharging part being between the first static dissipative part electrically connected to the storage voltage line, and the pixels, wherein the static discharging part discharges a static charge applied to the first static dissipative part to prevent a malfunction of the pixels,
• wherein
• the first test signal from the first test part is applied to the source lines through the first static dissipative part, and
• the first test signal is different from the common voltage.