I have a Pro-Form 660 cross trainer and it doesn't work for some reason. I can turn it on and the light go on and everything, but when put the key it nothing happens. I went to Sports Authority to ask someone about it. Someone went and got the manager. I thought that the problem was the key. When the man who was helping me left I tried the key out on the display model that they had in the store. The machines worked fine. I am very concerned and confused about this particular problem.