One guy laid his machine down in his van and got it home only to find the machine was acting strange...
When he opened it up, there were coins like...everywhere!
An S+ has a 1/4" slot about 3 inches long on the wall side on top of the power supply box...if coins ever fall into that...look out!
IGT made plastic covers to fit over the top of the motherboards to help prevent shorts from loose coins.
They also put a 1/4" thick piece of foam UNDER it to do the same job.
The stupidest electrical design I've ever seen though, has to be the power wire going over the top of the little power switch box.
The only protection is a plastic wire wrap.
It would have been much better to have an exit hole coming out of the rear of that box
protected with a heavier plastic strain relief cord retainer plug.
I guess it was out of the budget for the original design.