JBJ ATO Has Stopped Working

[rhudgins]

I have had the JBJ ATO for over a year now set on Mode A and all of a sudden it has stopped working. All of the sensors are clean. The light for sensor one turns on when the water level in my tank gets low and the yellow pump light turns on but there is something wrong with the signal to my pump because it will not turn on. I found that if I take sensor two out of the fresh water reservoir and manually push the white sensor to the top of the casing and then let it fall to the bottom of the casing then the pump will turn on. That is the only way that I can get the ATO to work. Does anybody know what the problem is?