To check an input to see if it is working, go to the test menu and press on input. The below screen will appear allowing you to see the inputs. If an input is on, the dot next to that particular input will be green. To test an individual input for proper function, simply activate that switch or button. 

For example, if you want to see if the 7-pin whisker is working properly, move the 7-pin whisker assembly and the green light should appear next to the input test whisker seven pin.