First make sure you didn't turn off sonar in your settings then next try doing the factory default reset to set it back to original factory setting. Next thing if that not working is to find someone that has a unit like yours and see if it works with there transducer. Also check all of the transducer wire to make sure that a rat has not made a meal on the transducer wire. Hope this was some help please let us know if. how and when you get it fixed to help others also with a problem like this.