I have a Janome 6600. When it was new, I was sewing and took my foot off the pedal and it kept running, when I put my foot back on it stopped. Did this several times and finally I turned it off and turned it back on and it was fine for about a month and it did it again. Called the dealer and of course he said he had never heard of such a thing, but would call the company. Within a few min he called me back and said the company said a module was not working properly and the only way to fix it was a new motor. Of course being new it was covered. After the new motor I have sewed on it for several years with no problem. Hope this will help.