Abstract: A display device having a plurality of select lines includes redundant select line scanners. Each scanner includes a plurality of substantially identical stages having an input terminal and an output terminal. The stages and select lines are ordinally numbered and correspondingly numbered stages are connected to opposite ends of the correspondingly numbered select lines by separate line segments. The stages within each scanner are cascaded by connecting the output terminal of each stage to the input terminal of the immediately succeeding stage. The select line scanners are independently operable by the provision separate power supplies and clock generators. During testing, one scanner is made to look like a high impedance to the scanner being tested. Failed stages of a scanner are replaced by the correspondingly numbered stage of the other scanner simply by opening the separate line segment of the failed stage.