I have done things like that, too. I was doing applique work and thought that I had ruined/tore up both of my Janomes's. Took them in the serviceman got things up and running just fine. Brought them back home and after about 5 minutes, everything was messed up again. took my machines back and lo and behold, discovered that the heat'n bond on the back of the applique was gumming up my needle and thread. I learned several lessons that day.