Array substrate and fabricating method thereof, display panel and display device

A system, comprising:

• an array substrate, comprising:
• an indium gallium zinc oxide (IGZO) film layer;
• a gate layer with a disconnected portion at a position thereof overlapping the IGZO film layer to form a first gate line and a second gate line, the first gate line and the second gate line being configured to detect conductorization of indium gallium zinc oxide;
• and
• a gate insulating layer disposed between the IGZO film layer and the gate layer, and provided with at least two through holes thereon, wherein the disconnected portion is between the at least two through holes, the first gate line is connected with the IGZO film layer through at least one through hole, and the second gate line is connected with the IGZO film layer through another at least one through hole such that the IGZO film layer is connected in series with the gate layer.