reefkeeper light

I was doing a water change last week and all of a sudden my whole controller system shut of, so I went and checked it to see if water got on it and no evidence was shown? I looked very carefully with flash light to make sure I didn't miss any details then i checked to see if anything was loose, but nothing. Then I unplugged one of the cables going to sl1 to the plug in strip that comes with the controller then lights came on, but that was it?