Generally, when they jam I dismantle them down to the black ring and spring at the base of the spindle, clean everything up and put it back together with a little 3-in-1 oil where it might help. I always check the base (perspex) ring to see whether any of the 'teeth' that mesh with the black base ring are broken, and if necessary swap base ring round with next one which is fully intact.
From a brief search of this site, the problem sounds like it might be a 'dropped barrel' but although someone referred to a 'fix' described by 'Gary' - I can't find his posting.
When a coin is inserted and mech turned, one pot drops into the barrel but also a fraction of the pot above. So if you don't flick the mechanism round fast enough, the 2nd pot jams the whole thing. I can fix by turning upside down or pushing the barrel up manually from underneath but on a couple of sites now, but that's not going to work for my customers
Alex (tubz vending/Hurleys vending in Hampshire and West Sussex - please feel free to pm me if you're close by!)
