I think this is what Ringalong was talking about, found this on another site: Make sure that the flight sticks are going in the right direction, some guys had to reverse throttle channel, some had to reverse elevator and throttle channels
If the Tarot is in Failsafe mode it will not arm so double check flight mode switch that it is not in Failsafe! Also, motors will not arm if USB is connected. And not to bring you down, but the ZYX-M is notorious for being DOA. Hope you just have a minor problem and not a dud.