Instrument Cluster Problems

Ok i have a 1986 BMW 325 and basicly the temp guage and the Tachometer are not working i thought it may have been a loose connection but i took out the cluster and everything looked good. Any one have any suggestions?

there is a circuit board that goes across the bottom of the cluster.. it has 2 batters in.. you could try to change the batters or plug in another board.. this is a common thing for this car...