Hi Robot,
I've got to agree with Uncle Dave. I mean, you wouldn't but a car, new or second-hand without at least test driving it. Return the Juno to the dealer and demand either a replacement or, at least a refund.
Maybe it's a chip that's not working or maybe it's a fault in the wiring loom. Whatever, when buying any electrical equipment, be it PC, keyboard or even a cell-phone you should at least check to see it works before leaving the shop.
Enough of my rash comments for now...
Regards,
Michie