I bought this new at a resale store. It wouldn't turn on. I was bummed. After a little research and reviews, I discovered the flaw (or the secret). Remove the handle and slip up or remove the black insert inside the handle. Viola! The small tab which depresses the based safety switch is now in place. 

Is it a design flaw or assembly flaw? I don't know but it works. [This review was collected as part of a promotion.]