I'm not a super hands-on technical person, and mostly have learned how to repair stuff as I go, and perhaps not to the standards of a someone you might describe as "competent". I don't have a "workshop" space, and tend to just fix stuff on my couch and/or coffee table when needed.
For working on random coin-op, here are the 6 tools I appreciate the most, but which I hadn't realized I'd need when I started:
|1) digital micrometer|
2) leaf switch adjuster
3) telescoping magnet
4) angled-wedge lifter thing that kind of looks like a screwdriver? Also has a magnetic tip.
5) dental pick
|6) wood clamps|