Hi all,

we have the ‘76 Williams Grand Prix game and unfortunately the Number match unit stepper/alternator has died. The part that died is the actuator plate that indexes the 10 way stepper and also provides the alternator function for the top out hole bonus (left/right bonus advance). unfortunately this part is very rare and therefore almost impossible to source a replacement in Europe.

We’re running the machine in free play mode, so the match function is not really needed - however the alternator function is needed and affects the gameplay. it means that the top outhole only advances the bonus on the left. hope this makes sense.

i was thinking about switching off the match function and replacing the unit with a home-made flip-flop alternator unit made from 2 or more Em relays to replicate the function. Each ball hit on the top switches toggles the bonus avance left-right-left-right etc.

anyone else done this - if so does it work well and is there a circuit available and relay spec?

Any help would be most welcome.

martin