Well it may be broken real good. Others have reported breaking the magnets loose from the motor when hitting a solid object with the blade. Also, could be something electronic. Going to need more detail for any diagnosis here. Best bet is probably a call to customer service. Call first thing in the day to avoid a long wait - it is a busy time of year. You can also leave a call back number. You will likely need to bring it in for repair, but you never know so give them a call.