Hi, just to be clear and keep people from getting confused, let me define a couple of terms.
-The MultiMedia Lite II board alone does nothing. It installs piggyback on your MPU, and with the use of the DSV00042 Simm card, will provide some additional game sounds. The DSV00042 is the "generic" sound simm for non-game specific sounds (fancier sounds at Spin, Wins, Cash Out, etc). Certain game themes have game specific sounds, some games do not and can only use the DSV00042.
-The MPU is the large board on the silver tray that contains your game software/eproms and battery. The motherboard is a small 5"x11" green board mounted to the back of your cabinet.
-A Keychip is used only to access and change certain menu options. It is not installed all of the time. The S2000 key chips have not been revised for many years. They all perform the SAME functions. There are different Key chips for different operating platforms (I-Game, S2000 Reel Games, 039 board, 044 board).
Here are pictures: 1st is MPU with a MML2 sound board installed. 2nd is pic of a motherboard.