现象转动轨迹球 ,“十”字标尺无移动迹线。检查首先用纱布蘸些有机溶剂（如无水酒精等）清除轨迹球体表面的油污 ,以增大轨迹球表面的摩擦力。然后快速转动轨迹球 ,偶见标尺有上下或左右的动作迹线。因此 ,基本上排除了光耦控制电路及外围元件故障的可能性 ,最大可能是带动光? The phenomenon of turning trackball, “10” scale no moving track. Check to remove the oil on the surface of the track ball with gauze and some organic solvents (such as anhydrous alcohol) to increase the friction on the surface of the trackball. Then quickly turn the trackball. Occasionally, the ruler has up and down or left and right motion traces. Therefore, the possibility of failure of the optocoupler control circuit and external components is basically eliminated. The greatest possibility is to drive light.