Active matrix substrate, display panel, and testing method for active matrix substrate and display panel

An active matrix substrate comprising:

• a substrate;
• a plurality of gate lines arranged on the substrate;
• a plurality of source lines arranged on the substrate, in a direction orthogonal to each of the plurality of gate lines;
• a gate short-circuit line arranged on a peripheral region of the substrate to short-circuit the plurality of gate lines;
• a source short-circuit line arranged on a peripheral region of the substrate to short-circuit the plurality of source lines;
• a plurality of gate line thin film transistors each provided for a corresponding one of the plurality of gate lines and each having a source electrode and a drain electrode, one of the source electrode and the drain electrode being connected to the corresponding one of the plurality of gate lines, and the other of the source electrode and the drain electrode being connected to the gate short-circuit line;
• and
• a plurality of source line thin film transistors each provided for a corresponding one of the plurality of source lines and each having a source electrode and a drain electrode, one of the source electrode and the drain electrode being connected to the corresponding one of the plurality of source lines, and the other of the source electrode and the drain electrode being connected to the source short-circuit line,
• wherein the plurality of gate line thin film transistors and the plurality of source line thin film transistors are of depletion-mode, and
• the gate electrode of each of the plurality of source line thin film transistors is connected to the gate short-circuit line.