I only get that when i use the legendary option. =)
When using the Legendary Weapon option the three heads line up and the machine just sits there doing nothing. Deactivating the jackpot editor will cause the machine to give a random reward and allow them to be used again. The Large Moonstone option also didn't work for me. I haven't tried all of the options but I did try the Cherries, Bandits, Legs, and 777's and those all worked fine.
where do i find the Golden Chest for the keys ??
In Concordia there are two little outlets of land in the center, one with a shift machine, where you would enter codes for the keys if you were playing legit, the other has the chest you can open with your keys. So you're looking for the giant hole in the ground in the middle of Concordia.