Most likely is a bad motor - sometimes can be started using odd instructions. 1-Open door and hold down door switch with one hand2- Hold down start button with second hand3- Manually spin drum with third hand (probably need two people for this)If dryer starts that way then motor is bad (this could temporarily buy you some time to get parts or new dryer) If dryer still doesnt start then something (usually sock) could be stuck in blower wheel.