Quoted from Code_Blue:

The whole saying you'll bring a technician by to check it out to make sure it works 100% is what strikes me as weird and would bring up red flags as a seller. What's wrong with your own ability to evaluate a pinball machine? I doubt you would've had a problem if you showed up and plugged it in to make sure it was in the condition described in the auction (which you don't link to or say what the *auction itself* describes as the working condition). Talking about bringing your guy in to go over every nook and facet just makes it sound like you're going to try to get a discount because a bulb is out.

Quoted from scottrogers:

If you need to hire a tech to inspect your purchases should you even be in this hobby? To participate in this hobby you need to have enough technical knowledge to do a pre-purchase inspection yourself (and know when to walk away). Otherwise just purchase a new Stern or buy from a local dealer who will warranty and come out to fix as needed.
As to the original topic, always test a machine running before buying.
Sounds like both participants in this deal dodged a bullet.