I am pretty new at all of this. I have a Roco Digital power pack and the train I have has slowed down alot. Put jumper cables in every few feet to help with electric but this did not help. Wheels on the train look a little dirty but not bad enough I think to cause this much of a problem. Train seems to be struggling to get power. Still getting power interuptions throughout the track. This is why I put the jumpers in. Any help or suggestions would be greatly appreciated.