Faulty RPM Gauge ?
 

My RPM pointer occasionally flickers up and down as engine rpm is constant or even at idle the pointer just flickers from 1000 to 7000 then stays around 4000 and from there flickers to 7000 rpm for a minute or so before return to zero and then back to normal.

Any idea on what is the problem here ? RPM gauge dying ? Car is WRX MY98.

Thanks.

My speedo does similar and i have been told that it is sometimes due to dry joints on the gauges PCB.