Apparently he had a power cord that worked. I did find that interesting, since he didn't have any knowledge of sewing machines.
I think I had a Bernina or Janome with a power cord was very common. I actually think I had a boom box or stereo or some such thing that took the same cord, so this is probably what was used to test it.
I know someone with this machine, bought it new when they first came out for $1200 (I actually think they cost more now). Never any problems with it and just loves it, so if it works I think you got a great deal.