I own a Savamco Mac-22, which I've also seen listed as a Fro-Mac Snack/Drink Vending Machine. Mine is Grey/Black and I am in need of the schematics for the machine. It's intermittently not accepting cash and sometime will only accept up to 2 dollars. It has worked completely at various times.

I've got an electrical engineer friend who offered to look at it, but documentation is really hard to find. We've already replaced the coin-co bill acceptor, checked the DIP switches, made sure change was in the reserve.... at kind of a loss unless we could get our hands on some more info...

Is it going to be possible to find schematics?

Is there a solution we might be overlooking? 

Should I bite the bullet and buy a new control board on ebay? There is one currently listed for 350

Any help would be greatly appreciated!