Not quite the same thing, but I understand your frustration. Years ago I worked at one of the colleges here in town in the theater dept, costume shop. We had a industrial serger that wasn't worth a ................. Would keep coming unthreaded, lost tension, etc,etc.etc It had been purchased by the previous costume design teacher that for some reason when they left, the took what little instructions on how to run it with them. The thing was finally junked.