Bally Big Apple Bonus Game Issue

[big_e]

Hey guys,
I really need a schematic to dig into this, but when you get 3 stars, 3 cards, or 3 bars you light the Apple at the top of the game and then get 10 chances to get an apple on the 3rd reel.  This is actually pretty easy and you end up getting another 100 coins for a couple times with the apple.
Last night we hit it, and if you pulled the handle quick, reels spin, stop, and pay (if it should), then decrements the bonus one.  So if it is at 10, it goes to 9.  9 to 8 etc.  So if you pull quick all works.  If you pull slow it decrements once when the reels start spinning, and then once after it stops.  So you lose bonus spins.
Any idea where to dig in?

[Amechanic]

Pretty neat looking machine.. I've actually never had one or worked on one.. The person who might know would be Jon.