E30 320i Rev counter not working

[lunchbox]

Bought a 320i with a non working rev counter, and got a spare set of clocks which I fitted. The Rev counter still didn't work. Tried replacing the service batteries and got some slightly different lights on but the rev counter doesn't work. Mixed and matched a bit between the 2 clock sets and service boards to try and get it to work but to no avail.

What else can I try?

[road_rager]

dry solder joints in the instrument binacle? my e30 had loads