I purchased an extra c2000 Hamilton controller. I have always wanted an extra controller but I also want an extra Mars bill acceptor. I was testing out the new controller and it had a weird problem. It seems to shut down if you put in 3-4 bills in less than 30 seconds and then it restarts after 5 minutes. It did this 3 times in a row and I will email Randy and see what the problem could be.