Any ideas on how to revive an 83 tach?

[mrguitarz]

Somehow the screw that held my speedo plate on came loose and undone, and caused havoc on my tachometer.  It no longer works.  I replaced it with an 82 tach and it works, so that eliminates something outside being broken/unconnected.  I have it all taken apart and want to know if anyone has had this happen, and if there is one of the chips/resistors/caps that would be more likely to go bad.  The screw was lodged in the greenish windings on the tach part.  Thanks!

---Matt

[YellowJacket!]

The greenish windings are the electro magnet that generates the "field" and moves the tach needle.  If the screw got lodged in tere, it could have nudged it a little and caused it to be out of allignment.  Also, if the screw touched anything on the circuit boards, it could have shorted something out.
I messed up two tachs trying to change the old faded faceplate with a new custom one.  They are pretty darn sensitive.

David