Quoted from rotordave:
Pinball machines are historically designed to be run 24/7.
Also designed to be in a landfill in 3-5 years as well, I'm sure none of the manufactures thought any would be around 50+ years in some cases.
In my business I have seen too many things catch fire for "no reason" I'm in the better safe than sorry camp. One guy on a Mopar board just lost his garage with cars in it last year due to a cordless battery pack charger burning while he was out.