The attached images are of control heads (i.e. user interface) for a marine auto pilot I've been reviving. In one I've circled in red flexible posts that move up and down when a dial is turned clockwise or counter-clockwise. The posts are capped with conductive rubber that make contact with the pads on the pcb. The posts are about 1/4" diameter and I get anywhere from 10 - 20k ohms with my multimeter probes about 1/8" apart on the pads. The second image shows the posts from two other control heads. The dial on the control heads with these posts will not work because the resistance is in the megaohms range.
Just to make sure that's the problem I stuck small pieces of copper trace tape on the posts and the control head's dial worked properly. I've tried mixing pencil lead in silicone and that wasn't conductive. Anyone have any experience with conductive silicone? What other thin flexible material might work to restore conductivity and stick to the posts? Thanks for any ideas.
Just to make sure that's the problem I stuck small pieces of copper trace tape on the posts and the control head's dial worked properly. I've tried mixing pencil lead in silicone and that wasn't conductive. Anyone have any experience with conductive silicone? What other thin flexible material might work to restore conductivity and stick to the posts? Thanks for any ideas.