I do not have the problem (yet) but I like to be informed to prevent any damage. I read a lot about the tie back on the drop target in STTNG but I did not find any clear, simple answer to the solution. As soon as the thin purple/green wire on the drop target coil gets loose the 8 driver board and the diverter on the subway gets damaged. There is a method of preventing this but I did never understand what to do exactly. As far as I learned it should have been done correctly in production but wasn't done in a lot of machines. Can somebody explain what to do - best would be by pictures!