I think a section has a short. The power pack would not be the problem, though I would suggest getting another one with a 5.0 amp output. And not LifeLike. Toss it or use it for lighting, not the layout. MRC makes a nice lower priced unit that is pretty good quality.
I would find the offending section, take a good look at it, and toss it if it can't be fixed.
Bob