After much trial and error. The recommended setup seems a bit hit and miss. Fortunately I found this link which explain why and how to setup the camera in detail.
http://www.astropixel.gr/uploads/7/8/3/5/7835053/scientifically_determining_ccd_gain_and_offset.pdf
The answer for all QHY10 users I think.
Hope this sort your problem too.