Does anybody know?

Depends on which tach you have. If i remember right, Captnimo does work on the digitron tachs and buys and sells them, as well as fixes them and sells parts for them. Id get in touch with him
If its a mychron just send it to AIM. As far as I know it's free labor and you buy the parts.
That would probably be me you're looking for. PM me and let me know what ya need. I fixed several tachs for a guy the other day for less than it would have cost him to get one of them fixed at Digatron.