I have used my ASI 1600 MM Pro cooled since November 2018 and it has performed beautifully. However. in the last six months, horizontal lines have appeared ( and ruined) some images. This occurs intermittently, say 6 or 7 out of 30 images. My set up has not changed ( cabling, computer, software) and the lines appear regardless of what filter in am using. Anyone seen this phenomena or have a suggestion? Jim Bradburn