Why can't I turn on my stand mixer?

I was using my Oster planetary stand mixer (for kneading bread dough etc) and it started making a very loud noise. As I reached for the switch to turn it off, it stopped working. It is definitely getting power to the unit. But when I try to switch it on , it remains totally silent (no humming etc). I unplugged unit and let it stand over night, but it STILL does not turn on or make any humming noise.

I have contacted Oster (Sunbeam is the parent company) several times , but they have not replied.

Can anyone please help me ?