Dryer has been shutting off and then when you push the start button it will buzz for an extended period before it starts again. After a few of these events it shuts off and will not make any sound and will not start. Element is working, vent path is clear and clean. Motor or a thermal sensor type thing? I'm wondering about motor because after I move it around to clean and get to the back it will start, but goes through the above process again.