An improved prober for an electronic devices test system is provided. The prober is “configurable,” meaning that it can be adapted for different device layouts and substrate sizes. The prober generally includes a frame, at least one prober bar having a first end and a second end, a frame connection mechanism that allows for ready relocation of the prober bar to the frame at selected points along the frame, and a plurality of electrical contact pins along the prober bar for placing selected electronic devices in electrical communication with a system controller during testing. In one embodiment, the prober is be used to test devices such as thin film transistors on a glass substrate. Typically, the glass substrate is square, and the frame is also square. In this way, “x” and “y” axes are defined by the frame. The electrical pins may be movable along the axial length of the prober bars, or may be selectively pushed down to contact selected contact pads on the substrate.