There is nothing that really can go wrong except the machine gets knocked about and something is out of alignment or loose. The repair maintenance manuals have trouble shooting checklists and plenty of photos showing how the parts are supposed to be positioned. Yes, Jukebox parts for virtually all models can be found in Jukebox Publications . Also many of the more popular jukeboxes have a full range of reproduction parts available for the cabinet. You can find a listing of dealers in repro and old parts on the Internet Links part of this site.
Many jukeboxes exist in homes, warehouses, etc.
Even though they are repairable, the labor involved does not justify the current selling price for restored or operating machines. You on the other hand can often justify restoring it if you provide the labor. They are nothing more than a remote set of selection buttons and a coin mechanism that was connected to the Jukebox. They were advertised to provide a convenience to customers, which they did, but their primary purpose was provide extra income, by having several patrons pay for the same song. This worked since at any given time, many people were making selections, usually favoring top hits, as the jukebox would could only record a single selection for a given song, it only played once, but each patron figured it was his or her selection.