You can't find the motherboard because it's a special one made for that model, there are no standard PC cases that will fit it. It's made for the case it's in, there are no standard power plug connections on that thing, nor are the port locations made for a standard desktop back-panel. There is really no need to move it to another case anyway, it's not very expandable past maybe RAM and a larger drive, it's pretty much a laptop without a screen build.