It’s a new printer to us – straight out of the box.  We’ve connected all the wires (including swapping two around on the mainboard, as they were mis-labelled), and pressed Auto Home.  When we do, the x and y do their thing, but the z goes up instead of down for its test and makes some horrible noises.  I can’t have put the wires in backwards, as those plugs don’t allow it.  The Auto Home fails every time as a result and I’m at a bit of a loss, as it’ll be a real pain to have to return it.