It's either a faulty burner spark switch (located on the burner valve) or a faulty spark module. Switch is number #5 and spark module is number #15 on this diagram. If you turn on the burner in question and none begin to spark, then it's probably the switch. You can typically spot the damage when visually inspecting the switch or use an ohmmeter to check the switch for continuity.

To remove the top, first disconnect power to the stove. Then unscrew and remove all four burners. You should then be able to lift the front of the top. If you can't, remove the control panel, you'll need to remove it to replace the switch anyway. Use this diagram.