You have a bad ignitor switch. Which is behind the knob. If you remove the knob, it's the white part that you see. They come wired together as a set. To lift the top, you have to remove the screws from each burner, then remove the screws under each burner, then use a putty knife to release the clips on the front. You will also have to remove the cover in front of the valves to replace the ignitor switch assembly. Try searching Youtube for Frigidaire range, this range is Friggy built.