Recently, I received an email stating the ball in a Williams Blue Chip machine would not kick out. If the ball was manually moved through the trough, you could play the game like normal. The ball would not kick out during the start of the game or any time the ball drained.

I started the repair by looking for some of the obvious signs. The outhole switch was working correctly and the wires to the ball release coil were connected properly.

Fixing the problem

I grabbed the schematics and looked for the Ball Release coil. This is the coil that kicks the ball out. The coil has to make a complete circuit and must make a solid path from the ground wire to the power wire. There is only two switches in this path. One is Score Motor switch and the other is on the Outhole Relay.

Ball Release Coil path

The Outhole Relay is activated when the outhole switch was engaged (ball in the gutter). This is what should happen when the ball drains. However, the Score Motor switch did not change states and that was because the Score Motor did not start when the Outhole Relay was engaged. This led me to cleaning and adjusting the outhole relay switch connected to the Score Motor.

Score motor path

Cleaning and adjusting this switch caused the Score Motor to turn, which closed the switch in the Ball Release relay to close. All of this now caused the ball to kick out each time. This fixed the initial problem, but noticed a couple of items that weren’t working correctly when I played a game.

Additional Problems

The game would not end on ball 5 and would kick out a ball 6. I could play that ball and then the game would end when the ball drained. This was a switch on the ball counter that needed adjusted. Once the switch was adjusted, the game ended after the fifth ball drained.

ball counter switch
Ball counter switch

The other problem that I noticed was the flippers were really wobbly. I lifted up the playfield and noticed that both bushings were broken. The EOS switch looked good on both and I replaced the coil sleeves while I had the flippers disassembled. I fixed the flippers and the game is now working like it should!

Broken flipper bushings


When I was looking into this repair, I saw someone mention a great little mod for this game. It’s adding a Fire Ball LED to the backglass. It’s such a cool effect on this game.

This is a fun game that I have only played a couple of times in recent years. I am glad that I got a chance to repair this game and get it back to the owner so he can enjoy it, too.

2 thoughts on “Williams Blue Chip EM Pinball Repair

  1. Doing a restore on a William Blue Chip, do you have any playfield plastics or know where I can get them? I have a couple fo broken ones I’d like to replace

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