Is the power light on your ninja blender blinking? Normally this means that your Ninja blender is assembled correctly. Make sure that the lid is firmly attached to the pitcher and pitcher is fully locked to the motor base. Also make sure the pitcher handle is aligned to the front right or front left of the motor base.
If you have checked all of theses it sounds like there is some sort of fault and you may want to contact Ninja directly toll free 1-877-646-5288