I've put off posting this one because the problem is unusual, complicated, and difficult to describe. My Williams Triple Strike has an odd problem with the end of ball bonus that only occurs under very specific conditions.

Short description: Completing a set of ten pins by hitting a matched pair (but not a single pin) causes the bonus to advance too far.

(EDIT: Problem was residual magnetism on the 1-10 reset relay. Fixed with a piece of cellophane tape.)

Background:

Triple Strike allows you to accumulate up to 39,000 end-of-ball bonus points per ball. There are ten buttons on the playfield that are laid out in a pattern like bowling pins, and they're numbered 1-10. The buttons are lit to start and the lights go out each time you hit one. Each button represents 1000 bonus points.

When you "knock down" all ten pins, they light again and the first X lights below the pin set to indicate that you have earned 10,000 bonus points. Do it again and the second X lights (20,000). Do it a third time and the third X lights (30,000).

Complication:

Just as in real bowling, you can hit one pin and "knock down" another.

There is a playfield adjustment jack that allows you to knock down certain pins in pairs.

Conservative - hitting button #7 also scores #10, and vice versa. (Order doesn't matter)
Medium - as above, plus #4 will also score #6
Liberal - as above, plus #8 will also score #9
Extra liberal - as above, plus #2 will also score #3

This setting has nothing to do with the problem; I've just included it for reference.

THE PROBLEM:

For simplicity, let's assume that I have the game set in the conservative position, so that hitting #7 scores #10, but the other 8 buttons must be hit individually.

When the last remaining pin is a single pin, such as #5, and you hit it, the pins all light again and the first X below will light to show that you've earned 10,000 points, as it should. This works if the last pin is any single pin.

HOWEVER - if the last lit pins are the #7 and #10, hitting either one of those will also score the other, will complete the set of 10, and will cause the X below to advance three times, rather than just once. Instead of showing that you have earned 10,000 points, it shows 30,000.

It doesn't matter if the playfield adjustment is set to conservative, medium, liberal or extra liberal, this scoring issue only occurs when you complete the set of ten pins by hitting a matched pair. If you complete the set by hitting a single pin, the bonus advances correctly. When it's a pair, such as #2-#3, #4-#6, #8-#9 or #7-#10, the X will advance three times instead of one.

This is a surprisingly complex game and I've gone over it again and again and I just can't find the problem. It's undoubtedly a single switch somewhere that's out of adjustment, but I can't find it.

Manual here for those who are interested in helping track it down:
http://mirror2.ipdb.org/files/2652/Wms_TripleStrike0001.pdf

Anyone have any idea why this is happening or suggestions as to where I should look?

Charlie

pin_adjustment_(resized).jpg
triple_strike_pins_(resized).JPG

I thought I already checked those score motor switches, but I'll check them again.

I fired up the game this morning and it lit all three stars even when the tenth pin was a single one. That simplifies the problem, but the solution is probably the same.

Thanks for the reply. I own ten EM machines, but this one seems to be more complex than the others (it's also my newest EM, so that probably has a lot to do with it.

Charlie

Easiest. Fix. Ever.

Problem solved. The 1-10 reset relay was the culprit; the problem was likely residual magnetism in the actuator plate that was causing it to be a little too eager to close.

I put a small piece of cellophane tape on the side of the actuator plate that faces the coil. That interfered with the magnetism just enough to make a difference.

The game works correctly now.

Thanks to Mikala for pointing me in the right direction.

Charlie