A friend called me about his Stern Roller Coaster Tycoon pinball machine and wondering if I could repair a few problems with it. The owner stated the following problems:

  • Error message stating missing ball even though there is four pinballs in the machine
  • Right flipper sticks
  • Right sling shot is dead
  • Left sling shot machine guns


The first problem that I looked at was the missing ball error. I figured this was going to be an opto problem in the ball trough, but ended up being wrong. When the machine was in diagnostic mode, I checked the switches and noticed four switches were not working.

This was the clue that I needed and then started to check the white with a blue trace wiring. What I found was a broken wire on the mini flipper stand up target. This also fixed the third problem, right sling shot dead, along with two other switches that didn’t register.

I ended up rebuilding both bottom flippers as the coil stop had flattened along with some slop in the flipper link. This also gave me a chance to use my Coil Sleeve Remover, and did a super job. This fixed the second problem on the list.

After adjusting the leaf contacts on the left sling shot, it no longer had a machine gun affect.

I noticed quite a few bulbs were not working and thought it was going to be a row or column issue, but ended up just being bad bulbs (or loose connections). I also had to replace two flashers. Finally, cleaning and waxing the playfield completed the repair.


This ended up being fairly straight-forward repair and glad to get it back to the owner. I have played Roller Coaster Tycoon a few times in the past, but nice to have one in shop to repair. It’s been a while since I have had a Stern Whitestar (NASCAR) in for repair. This also gave me some time to put some games on it 😃. The ramps are pretty interesting on this game and its definitely a kid-friendly game. More information about the game can be found on IPDB.

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