Jeff Barnett has a good page describing the repair. See http://mywebpages.comcast.net/jeff.barnett/tach.htmlDC Turismo said:new question for you: how'd you fix the tach? i heard you had to solder some of those prongs but not exactly sure how... please let us know if you can!
The circuit board he refers to is the tachometer drive module. You will want to examine this closely with a magnifying glass. It is difficult to see any breaks in the solder with the naked eye. On my tach drive module it was pin #1 that was loose (at top of circuit board).