I have a 1978 sonic cherry bell pinball. The machine was pretty much not working when i got it. I have the machine about 99% now. The problem i have is the 2 bottom lanes that are suppose to score 500 and advance the bonus only score 500. They do not advance the bonus. The top right lane does give 500 points and advance the bonus like it should. I have checked the bottom switch on both of the bottom lanes. The switches are good. I even jumpered across them and still no bonus advance. Does anyone have any suggestions of what to check?

DrawOnPhoto_1486609197409 (resized).png

Thanks, Yes i have the schematics. They really dont show the wiring. Well maybe they show more than i think and i just dont know how to read them good enough for that yet. I brought it back from the dead using the schematics but this has me stumped looking at them.

Thanks, The bonus unit works good. Every switch advances bonus like it should except for the 2 bottom lanes. The top lane and both star buttons advance bonus as it should.

When you say orbit switch what do you mean? Thanks

Thanks for the replies. By using the schematics i found that a wire had broke off of the bottom right target.

Yes it is working 100% now. Thanks