We have harwood floors and only 4 floor rugs so it doesnt get a lot of use. Last time I used it the cord in the back would not coil back in so I rolled it up. I got it out and it will not come on . I have tried several outlets...not that. I want to get inside of it and swee if cord has pulled out of insider of unti. The power source seems to be the problem . I see no screws and can't figure out how to get inside unit, please inform.