I just recently bought a Game Boy for $4.99, even thought I wasn't expecting it to work (too cheap). When I was able to turn it on(without cartridge) it shows a black horizontal line and below a black rectangle with the registered trademark 'r' at the right corner (when the contrast is low) or a black screen with some lines in a white-greenish color. Is it supposed to look this way, or is my Game Boy not working properly? Is there some way to fix this?