Having worked in home restoration and renovation, I can tell you with absolute certainty that learning how to diagnose and repair pinball machines is a completely different animal than "bigger projects around the house." I spent two years of college in computer engineering school before switching to business school, and reading schematics is still very foreign to me. In fact, last night, after three months of pinball ownership, I had my first AHA moment where reading a schematic made perfect sense to me. I credit the above-referenced www.allaboutcircuits.com for that moment. It's rather math intensive, and sometimes feels like homework, but the understanding you will gain, even just in qualitative analysis will be invaluable. It will take some time, but I'm working through it at the same time, so if you have any questions feel free to pm.