imagePROGRAF PRO-4000S Ink Streaks when Printing

[biomedposter]

I have a Canon Pro 4000S printer, 42" wide. It is used in a University Lab to print large research posters. About 3 weeks ago it started to leave ink streaks on the paper edges. I would run a print head clean but it would still come back. Now it is worse and the streaks are in the center of the poster. 

[Lithoman]

That looks like media strikes with the carriage. Is the edge of the roll nice and wound or had it been dimpled?

What kind of media are you running, brand? Can you take a picture of the roll edges and post them?

[biomedposter]

How does it strike/how can I fix that? I ran another print but could not get a good image of the carriage. The edge of the rolls are not dimpled I will attach the images. We are running Satin Photo Paper and Synthetic Paper ( Fabric ). 

[Lithoman]

It will strike I the media isn't laying flat while transiting under the carriage. In the paper menu on the machine, select the roll the look for the advanced settings. Under there you can adjust the vacuum settings to help counter the media curl. Keep in mind the clearance between surface and carriage are pretty small. Have you run normal bond plain paper, how does it look?

You also said you run a synthetic fabric. Look for stray fibers on the carriage underside. These can collect ink mist and cause marks as the machine runs. Also look at the orange rollers on the media clamp. If there is ink or debris collected there it can deposit as the machine runs as well. Looking again at the photo, the step looks about right for the diameter of one of those.