#1.
Quoted from YeOldPinPlayer:Learn to read a schematic.
2. Read https://pinside.com/pinball/forum/topic/em-pinball-circuits-basics-to-not-so-basic
3. Read http://www.pinrepair.com/em/index.htm
4. Learn to use a multimeter
5. learn to use a soldering iron.
6. Review VID's guide https://pinside.com/pinball/forum/topic/vids-guides-a-pinside-compendium-updated-72015
7. Under favorite topics use "Topics linked to your games". (Someone may have had the same issue).
8. Before you post, read https://pinside.com/pinball/forum/topic/how-to-efficiently-ask-for-pinball-repair-help-em
9. Clean the male side of the jones plugs.
10. Invest in a leaf adjustment tool and Flexstone/Metal contact file.