Sorry to hear about your issues.
I know the feeling!!
My CN Turbo was problematic as well.
The major issue were the small wires used to connect the cars and engines.
The constant tugging broke many of mine.
You may want to look for broken wires in these areas.
When all the wires are in place, soldered back on ect.....seal them in glue at the area where they meet the plug and about half an inch down the grouping of wires.
The tethers are weak spots on these engines and too short.
Since this fix (and a return to MTH for a bad board) I have been problem free....so far.
Best of luck........I know how frustrating these issues can be.
I've had better luck, generally, with MTH than the Big L.
Soo Line
