This thread certainly explains why my Janome 6600 doesn't match the instruction book that came with it. I only have one plate (the book doesn't even mention two, AND it the pictures don't look like my machine! yes I bought it new). The nearest repair shop is a long ways away and the repair man has shown DH and me how to care for/clean. But when it was new I found myself calling him every month or two. He would always say 1) try a new needle; check the size; 2) check the bobbin area; 3) rethread (DON'T just check it, rethread!); 4) calm down... go get a glass of wine; 5) if none of this works, call me in the morning... Love that man! There is obviously more than one Janome 6600!