Instead of telling them what's wrong, it is a lot better to remind them what areas should be checked. This will lead them to some basic troubleshooting skills down the road. For example, "why don't I see a picture on my T.V.?" Kids should be able to list the possible points of failure and go through and check the basics - both ends of the cables (are they plugged in?), the power cord (is it plugged in?), the source of the signal (is it on?), the source of the electricity (is the power strip on?), etc.