Although I'm not a newbie to pinball, I was lucky that my first two machines were steal purchases of great condition huo mid 90's dmd games. I've done a little mechanical and electrical repair, and the full shop job I did on demo man was a beast, but I've never pulled a playfield or stripped a cabinet before.
It's been a few years since I bought a game, and despite resellers generally ruining the local Craigslist deals, I still keep a pretty close watch for interesting games. I just happened to find a special force and a flight 2000 on the same day from two different sellers less than 25 minutes from my house.
I went late on a Saturday to look at Special Force, and the game wouldn't boot. The sellers swore it was working the past week when someone else came to look at it. They didn't know squat about pinball as it was an inherited family member's game, and I didn't know squat about bally 6803 games. Also, I forgot my pinball tool box so I couldn't even change out fuses to check the simple stuff. They didn't want to sell it at non-working basement price, so they agreed to let me come back on Sunday to mess with it.
After poring over pinside for info all night, I went back Sunday and fooled around with no luck for a couple hours. I was about to give up when I read about the little pot on the power board. A little contact cleaner and a couple turns, and "it's alive!" We did the deal and I brought home a game with all the plastics and parts in good shape with not a whole lot of playfield wear. It sat in the garage for a couple weeks before I finally moved it into the workshop to start on it.