We just purchased an OCE 9400 (used from our sister company). We had a service company come out and prep the plotter but after he left we noticed that the printed horizontal lines are jagged at the same location all the way down the print. I believe we're using the Windows driver. We've contacted the service company and looks like it's going to cost us another service trip (+ travel time). They think it might be a circuit board. With just having them here and prepping it we can't justify paying for them to come again at this time. Has anyone seen this problem or know of a fix? Thanks