I have a nice Bally Harley Davidson 1991 era that plays well except the lane change does not work. I am looking for some help troubleshooting. I have the schematic that shows the lane change circuit landing on J102 but examining the power driver board that does not look right. I wonder if that is an error in the manual and that J120 is not the right connector but it is configured slightly different. Also where do those components in the dotted box reside and I am not quite sure what they are? Regardless I need some guidance on where to start troubleshooting. I have not worked on a WPC89 machine yet.

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So U7 and U8 is maybe where I should look? I found it in the manual now thanks. I can try and probe those chips out. I also show a switch error on 11 and 12 right and left flipper.