I just made the leap from puttering around on classic arcade cabinets to puttering around on pinball machines. I can (mostly) read a schematic and can (mostly) use a DMM, I've done a couple cap kits and flyback replacements on arcade monitors, but I'm not really an electronics smart guy.
I picked up my first pin, a Paragon, a couple weeks ago from a guy whose business is arcade/pinball machines. He'd picked it up with another machine but realized he wouldn't have time to work on it. He said he'd plugged it in, got some GI, heard a cap blow (C29 on the solenoid board), then unplugged it.
I've done my due diligence for research and at this stage am following the "Repairing Bally Electronic Pinball Games from 1977 to 1985" guide. I also have the original manual that came with the machine. I spent a few minutes with the MPU, noticed some corrosion but I don't think it's very bad at all, and removed the battery. Then I set the MPU aside to focus on the power supply.