Pro Form 770 ekg treadmill won't start?

We bought a used iFit Pro form 770 ekg treadmill. It won't start, and I'm wondering if there is something wrong with the orange key. Can we purchase a new one somewhere? The treadmill appears to have had very little use and looks almost new - but it won't start. We've checked the plug in for power - it works fine. We've "jiggled" the key card, but still nothing. Help!