Lee Smith (ada DJ Legion) took a faulty Pioneer CDJ-100 digital CD Deck and turned into a MIDI device.
Lee is a DJ on the weekends at a large club, and by day repairs Technics and Pioneer gear. The challenge of retrofitting a dead Pioneer CD Deck was right up his alley. He published a great 7 part video series on the process. You can find the videos here on his You Tube channel.
Code for the project can be found on GitHub.