I am posting here in lieu of support from ZWO which currently is not available. My ZWO 7 position EAF stopped working. It will not calibrate. The wheel seems to turn normally, but when I select "recalibrate" it gives an error message to move the O ring, or just keeps spinning. Either the sensor is bad (which I actually kind of doubt), or it needs a software reset. Any suggestions? I hope its not another trip to China!