Sorry - I don't understand the last post.
But.... if they are not going back to zero but the game still plays like normal then they had found their zero position.
Game wont let you continue unless the scores have found zero position. So it would seem that even though you can see a number, the relays are behaving normally, Sounds like the reels themselves are disengaging and spinning round which is what Millsy is suggesting
I hit the start button and the score reels don't move from the score set on the previous game. So if I scored 24320 then that is the score I start the game at. The credit reel moves, targets reset and ball count starts at 1 and everything plays as it should with the score reels scoring correctly throughout the game. The game awards specials and credits at high scores corresponding with the score displayed and correctly awards match replay with matching numbers. When that game finishes and I hit start again, this time the score reels all go back to zero and the game plays as it should. The problem is sometimes the score reels don't zero at the start of the game; it's all the reels that don't zero and they don't make any noise and don't spin or disengage at all but then that game plays and they score perfectly throughout the game and everything else works perfectly too.