A year ago, the Z rotation on one of the sticks would malfunction. The response was the axis flipping to and fro, almost through the whole range, also to be seen in the Windows calibration settings. I had 2 old used ones, so I replaced the pcb in the stick, problem solved. Now, the problem was back. Replaced the corresponding potentiometer, no result. So, reluctantly preparing to replace the pcb again, I fiddled around a bit. Guess what. All I did was to unplug the white plug with the 5 connections and to plug it again. Stick is perfect again. Just unplug and plug that thing a few times, to clean the connections. I write this here because, as it has happened to me twice by now, it might be a problem that other Citizens might also have.