We have a TMFX II so I'm not sure if the controls are the same but we can turn off the upper thread detection by pushing F2 to #5, TD:, select 1-5 which is consecutive thread breakage times. A dash is no detection. If its just certain needles, Hirsch had me spray LB5 in the slot behind the tension knob where the take up spring comes through. Just a squirt, and don't get it all over the friction discs. They say over time the spring corrodes from mechanical action and looses its conductivity. That is really evident if you have red rust dust around the tension knobs. As for the trace I have no idea. If its the same year as your others check to see if they all have the same software version.