Many modern appliances have a "service mode" accessible by a sequence of button presses. This mode can yield error codes and operate individual components for testing. Interestingly, this high-tech approach to appliance repair originated from video games, using cheat codes to unlock special features. As appliances have evolved, these "cheats" offer technicians a diagnostic shortcut, resembling a secret language between the repairer and the machine. Share your own surprising facts about the hidden world of appliances!