As we all know the center rail of fastrack is brittle and can be easily broken. The easy fix is as follows:
turn track over and bend support flaps up ( you will need a small screwdriver or alike to stark the flap) one you bend up the flap to the center rail remove the broken pin. Only bend the flaps nearest to the end of the track and the next one back. You do not have to remove the entire rail, raise it just enough to get the old pin out.
You will need a flat piece of copper (this can be found in most hobbyists stores) 3.87mm by .92mm.
before you remove the broken pin take note what side it will lay on.
gently pry up the center rail, on the side the new pin must lay on, you will need to gently pry that side out just a touch. This is done at the first plastic riser that the center rail slides over.
the new pin (copper) must me long Enough to go from this plastic riser to the front of the track. Do not cut the copper but place it and then put the track together allowing for the perfect length.
the new pin will be held tight when the center rail is put back into place trapping the copper between the rail and the riser. Bend the flaps back into place cut the new pin and you have a perfect conductor that is also flexible.