The black bar appears when you turn it on with no cartridge inside. Try it with a game, you can tell any of your friends, make sure anybody will have a game lying around their bedroom inside a drawer. The battery light, don't worry, is to tell you it's on. You can have a blank screen because a game glitch as if it were turn off and you run out of batteries in no time. When the batteries are dead, the light is off, just doesn't turn on (a little trick is, if starts to flick the light, it's time to buy another pack of AA batts. The speaker drains the battery like !&&* too.)