Ya it does go forward a little then back so it is definitely looking for marker, I slowed move to marker setting and it seemed to help but I still never see the marker trigger on diagnosis page, the home switch is triggered reliably. I think I will pick up one of the usb oscilloscopes, I was thinking this one looked good for price https://www.amazon.com/dp/0201336421...ing=UTF8&psc=1.

I just hope that the encoders are the type that can be cleaned as I bet they are expensive to replace.