Most of the time when an electromechanical game scores extra bonus points
during bonus countdown it is due to a sticky (sluggish) bonus mechanism. If
this is the reason, then the bonus mechanism need to be disassembled and
If the mechanism appears fine and the extra bonus appears to be random then
the problem may be due to a loose pivot post on one of the the step-down
ratchets. These posts are usually pressed onto the main mechanism chassis
and if abused may wobble, causing the extra bonus score.
A relatively easy solution for the loose pivot post is to apply a spring to
the end of the post so that it counterbalances the wobble.