[woodcote]

Hope you had a good walk! And glad removing the digital pb did the trick. Next, sort the polarity of the SCP...

My favourite resource on tracks and wiring is the BSCRA site here - Chris Frost has put together something pretty wonderful. One of the diagrams is this one...

   

The ‘common’ bit is where the brake connects to either the ‘ground’ (-ve) or ‘positive’ on the power supply. Common ground is the top two diagrams, common positive the bottom two.

I read ‘wiring’ or ‘polarity’ (+ve and -ve) as what terminal on the power supply connects to the controller input. I’ve seen some read this as the polarity of the left rail on the track - ie the direction of travel - but I believe that is a red herring... it won’t have an impact on the controller in any way. So the top two diagrams are positive wired, requiring a positive polarity controller; and the bottom two negative wired and require a negative polarity controller.

A BSCRA transistor controller will be damaged on a common positive (negative wired) track as they are wired for common ground only. Most modern hobbyist controllers (eg the SCP, Truspeed) will have some protection - but worth connecting it correctly if at all possible!

I have checked a number of sites and can confirm...

1) the Scalextric Sport powerbases are common positive / negative polarity. ie the opposite of a club track.
2) Scalextric and Ninco plugs are wired identically, but it’s worth checking the SCP wire colours correspond to the colours on the Ninco adapter...

There are these pics on the BSCRA website here:

         

I hope that helps and doesn’t muddy the waters more!