Fisher Price Nature's Touch Cradle Swing - Not.... I'm trying to figure out if I should invest in

Question

I'm trying to figure out if I should invest in yet another package of four D batteries or finally toss this swing. The mobile and sounds work, but the swing does not. I have noticed in the past that sometimes this would have something to do with where I set the swing and how far apart the legs were (a mm seemed to sometimes make the difference). Once all it took was changing the batteries and the swing lasted for weeks before I needed to replace them, but now I've replaced them twice and the swing still isn't really working. Is there anything else I can try? The swing was purchased in early 2006 ( for my first son) so it is no longer under warranty.