1984 318i tachometer

I have a great little 1984 318i. Since i purchased it last spring I have not been able to get the tach to work. The nicads have been changed but no tach so far. Is there a way of checking the circuit board. It appears to be in good shape. Is there a line i can trace to the distributor or other???I'm sure someone else has had some problems at one time or another with the dashboard component.

Alzie :)

i have the same problem (tacho and economy gauge not working) on a 1989 318i. I have replaced batteries, reset service indicators and re-soldered all points on the SI board to make sure there are no bad connections. But the tachometer still doesn't work. Are there connections that can be checked?