On both C23 and E90 cameras (as well as with the CGO3+), I often find that the wires between the slip ring and the upper damping plate have been kinked or pinched. I'm always concerned that with movement and vibrations during flights that these small wires could be further damaged. I have begun "reinforcing" the wires using a short segment of heat shrink tubing that is long enough to be trapped under the upper plate mounting cover on the upper end and under the slip ring cover piece on the lower end. That way the wires are protected and are fixed at both ends to avoid flexing or pinching of the wires. It seems to work fine. I thought others might be interested in this preventive "fix." You will need to detach the wires from the contact with a soldering iron and re-attach them once you have the heat shrink in place.