Canon imagePROGRAF Pro 4100s - Small black lines appearing randomly in the print head movement direction

[unique-posters]

I'm experiencing small black lines appearing randomly on prints from my Canon imagePROGRAF Pro 4100s, aligned in the same direction as the print head movement. We've tried the following troubleshooting steps:

• Cleaned the print head (standard cleaning only)
• Printed the nozzle control pattern - looks fine, except there are occasional minor, almost unnoticeable issues where black ink is printed.

Please see the attached screenshots of the issue. I hope you can help identify what might be causing this.

 

[DYP]

Looks like a fuzzy or something under your print head carriage. Have you tried cleaning the bottom of the carriage?

 

[TJPrinter]

I think it's caused by ink under the head too. If after cleaning under the carriage you still get the same marks make sure that the head isn't too close to the paper, either select a different paper type or go into your media configuration tool and adjust the head height.

 

[unique-posters]

Thank you both very much for your suggestions.

We carefully removed the head and cleaned it gently and thoroughly. Although there are now more black lines than before, they are less noticeable. The lines appear roughly in the middle of the paper when viewed from the front of the printer as the paper exits. Previously, we had stripes across the entire print (aligned with the direction of the print head as well) but resolved that issue by adjusting the print head height. The printer has been in use for a long time, and these new lines have suddenly started to appear. We will try to adjust the head height again.

 

[DYP]

Did you clean the underside of the print carriage? Not just the heads.

 

[Widmark]

Do you clean the platen? The issues I've had with the canons is ink building up in the holes on the platen enough to transfer to the bottom of the printhead, and then to the top of the paper. Regularly wiping down the platen and the holes that ink goes to (whether printing borderless or not) has helped.