So that 'sparky' disc must be lighting the pf spinner lamps? Just wondering since the arcing continues even after the unit stops. That's pretty nasty arcing if it's only lighting one lamp.

From the video yes it does look like carbon track arcing as mentioned, but that means arcing at the gaps between the copper pads, not between the wiper and the pads. As long as your wipers are stopping relatively close to the centers of the pads and not shorting across them, the new board should fix it long term I think... about as long as the old one lasted anyway. The tracking is something that normally happens over a very long time of use.