I have a resillence swg and when I turned the pump on the power comes on, but none of the other lights that tell % of ch are coming on. What does this mean? I know I have 3800 ppm in the pool. I cleaned the cell about 4 months ago. Does it need to be cleaned again. I did notice that when I came home for lunch the pump was trying to bring in water, but the level had dropped too much.