We've got a Road Kings here, and I keep getting reports that it randomly locks up in the middle of a game. The CPU board had some minor corrosion on it that I sent out to have repaired. The person who repaired it didn't really do that thorough a job - he just pulled some ICs out, cleaned under them with alcohol, and then socketed the same chips back in. It's entirely possible that some kind of corrosion is affecting the game.
I hear that the game stops working, the lamps and displays shut down, but the music keeps playing. I don't know if the coils still fire or not, as I'm not able to reproduce the issue myself. It always seems to happen when I'm not around. I know that Clay the Pinball Ninja walks into corroded board situations all the time and is able to pick out the exact component that's causing issues. But his issues are usually much more easily reproducible than mine.
Short of putting my work desk next to the pinball machine to catch the failure in action or replacing every single component that even LOOKS like it has a smidgen of corrosion on it (which I may end up having to do) what are some tests I can perform to figure out if the failure is because of one specific component?