Kenmore Dryer mod 110.66944500 not tumbling

Start button not working dryer was completely dead, lights working? This generally points to one thing in most dryers. A defective door switch. There are possible other causes such as the dryer only has 120v going to the machine, the push to start button may have falled and the motor could be broke also. Im just saying 9 time out of 10 the door switch is the issue.
 Start with unplugging the machine, always unplug the machine first! Then remove the two screws located under the lent collector on top. Next with a putty knife insert it at left and right corners and pop the top. Remove the door switch connector and check for continuity with the door open then closed. If there is no continuity the switch is bad, replace door switch with part number 3406107.