A friend of mine had a foot peddle that did the same thing. We were at a class and she really needed the machine. She was desperate and I have always been a curious person, so I took it appart and did something, I can't remember what, pushed something back into place (I think) and the foot pedal worked fine after that. She didn't even need to take it to a shop.
I am not suggesting that you do this, I am only letting you know that it could be a very quick fix by someone who knows something about machinery. Or if you are a 'fixer' type person and curious like me...