I replaced the original "genuine" RepRapDiscount Smart Controller assembly with a Big Tree Tech version which i was able to obtain in short order from Spool3D.ca.
For those not aware, there are two different orientations of the cable connector headers on the various RepRapDiscount Smart Controller versions and vintages. I vaguely recall reading a thread somewhere that suggested that the original design had an error on the header shroud silkscreen outline which, after a few years, was corrected. But i am of an age were the mists of time and the recent past are equally opaque so take that with a healthy dose of salt. In any event, i had to invert (i.e. rotate 180 deg) the orientation of each of the cables at the RAMBo to Smart Controller Adapter end. This is easy to do as the header shrouds are conveniently absent from the adapter board...