Just a thought BUT is the BOB powered up by 120vac ?? I noticed in your picture that the power lead is sitting and probably touching the incoming data line from the Printer port. IF that is a 120vac line then that is a big nono as the 120vac will cause all sorts of problems to the data line.
What we really need to know is DOES all the dros show movement or JUST the one that is commanded to move ?
Just a thought, (;-) TP