I was recently given a Phoenix 283 by my grandmother. She hadn't used it in years and it was full of lint, so I took it apart a bit to clean it and somehow in the process I screwed up the tension knob. Does anyone have any idea how it's supposed to look/be put together? I keep trying different things but the top tension stays way too tight, even if I have the knob unscrewed so far that it's about to come off.