This was a great little device and I have always been disappointed that Apple discontinue this line of products. This device finally met its end when it accidentally found itself going through the wash inside a set of gym clothes.
Before throwing it out, I decided to pull it apart and see what has made it tick all of these years.
This enclosure was very difficult to get into. The back panel appears to be pressure fitted in addition to being glued in place.
Due to the complexity of this device, I have chosen not to create a complete schematic or PCB diagram. However, this device uses an unusual cable for charging and data communications so I thought it would be useful to depict the cable wiring.