Many users had trouble when they were using solar panel controller, but they didn't know how to deal with it. I suggest they can judge from the following two aspects.

       1. According to the indicator light of the solar panel controller, that can preliminarily judge whether the controller is good or bad.The following is thesolar panel controller's indicator light description.

       2. If all the indicator lights are not working, it may be that the solar panel controller is broken,return to the manufacturer for further inspection.