Man those conveyor machines really suck. It ate my $2 once =(. I know how awful! Haha I just avoid them.
I can't actually remember the last time I saw a vending machine type thingamabob... but definately not the one you guys are talking about. But, I avoid vending machines as a rule, because they uaully just eat my money
I'm pretty sure the code to get into Coke machines is 4-2-3-1. It opens the admiinistration panel but there is no option for a free Coke. That can only be done inside the machine