I don't remember there being one. Basically all that they have to do is plug the plug hanging off of the back of the sled into the module. The only thing I can think of that's a little off is that if they use the extension cable (don't know if you even have one), some of them were made incorrectly. They're supposed to be straight-through (that is, pin 1 on one side matches pin 1 on the other side and so on) and some of them had one pin misplaced or something. In fact, I'd just check that before I went and fix it yourself if it's miswired.