I had to replace the cabinet node board on my KISS Pro. After talking to Stern tech support I learned that the cabinet node board is by far the node board that fails the most. You should be able to do a node board test and see which board is the problem. Main symptom for my game was the start button switch quit working.

Yes, not only is there the issue of the cost of the parts, but your game is down and not earning. When I first started to route Spike games I considered keeping a whole node board set on hand until I realized that Stern kept changing the boards from game to game. Might be worthwhile to do it now as long as all the current node boards are backward compatible.

FYI, current cabinet node boards work in KISS as I used the latest one when my original cabinet node board failed, they are backward compatible.