My first electronic slot was a non-working Summit, which started its life as a Bally. I had no idea, and figured, I'd just replace the electrical cord, drill the locks, and waa-laa, I'd be playing it. Wrong.
I learned all about it from the school of hard knocks. It took a while and I developed a ton of knowledge about it. In my journeys I accumulated a manual and online, there's one expert who repairs and sells parts. Other than that, my own knowledge brought me to fully understanding the machine. At the bottom of this forum section, the last one deals in all other slots, and there are several posts regarding Summit.
Still, the machine works 100%, and actually, it's my favorite machine, so if the price is right - and you are willing to learn about it - it's probably a good deal. Otherwise, just look for an authentic Bally as there are more resources out there to tap into.
There are a few glaring problems with the Summit, which I have addressed and corrected. I would be happy to share if you go that route.