I don't know if this belongs here but I can give it a shot in this section.    my parents own a lovely 1973 pinball machine, but it has a few problems. it won't go out of 4 player mode, and the king is always lit up (pictures down below for context).  my dad can replace things on it, but we don't know where the problem is. we have all the manuals and diagrams for what everything does, and I was hoping someone here knows how to read those.    I couldn't upload the diagrams here because the size of the pictures as too large, so here's a google drive link.  https://drive.google.com/drive/folders/1s-M9r0yjM2bKFCA7Of-ZQg3lLqsukAZx?usp=sharing   I'd really appreciate any help with this. even just a guide in the right direction.