I recently replaced the PCB in a lion chief plus gp20. Seemed to run OK with all systems and functions operational except front trucks start to chatter and grind to a halt on curves. I cannot see any loose connections on the pickup or motor mounting. It seems to be a mechanical rather than an electtical problem but I question whether the rear motor with the sensor has something to do with it. What does the motor sensor do?
I also have a GP38 which smokes very poorly. Takes a long time for it to heat up enough to produce any smoke at all. I replaced the heating element without any success. I'm beginning to think LIonel Chief Plus products are of poor quality. I probably should stop buying them although they are an inexpensive alternative to the Legacy products or MTH command Control.