Quoted from PPS:
I'm not sure exactly how UL and FCC work, but my understanding is if you have a pinball 'product' for sale then it is required to pass UL and FCC, not sure how you get away without that - something I think for safety sake everyone should be expecting from any supplier of pinballs ...
UL is *ENTIRELY* optional for any manufacturer of any device. UL likes to make people *THINK* they're a government agency and required, but the fact is that they aren't. There might be a local government that requires a UL mark to be able to be used in public places, but that is a requirement put out by the locals. UL is a for-profit company that does safety testing and allows people to mark their device with their trademark once they meet whatever requirements they deem necessary. They may also help you to prove you meet national requirements (like what is needed to CE mark a device or get approval by OSHA or the FDA), but those are different than UL testing and their mark. There are 3 primary private industries that do this kind of testing and marking in competition: UL, CSA, and ETL. We've used all 3 at various times on devices I design (ie: non-pinball). They are all basically the same but slightly different in the details.
FCC on the other hand *IS* a government agency and has requirements you need to meet in order to legally use or sell products. Basically, they do have legal authority but the enforcement side of things is somewhat nebulous and usually involved local and/or federal law enforcement.
I don't know if there are any US federal regulations that a pinball machine needs to meet that UL might help you prove compliance with. Having a UL mark does not eliminate you from having any liability in the case of your device causing damage or injury. It might help you prove that you did your due diligence and were responsible in how you made your product (which might limit punitive damages), but it doesn't eliminate any liability.
From the conversations I've had with a couple of the boutique guys, they are basically choosing to be ignorant (officially anyway) of being aware of these regulations and choosing to simply not do anything on that regard. Basically, they would need to be caught in non-compliance. In the case of the FCC, unless they are shown to be causing issues with someone else, the FCC won't likely care.
My 2 cents of my non-pinball experiences with the organizations in question.