White Speckles in CMY & Vertical Line in Black – Canon imagePRESS C700 Diagnosis Help

[jswole14]

Hi all,

I’m having an issue with my Canon imagePRESS C700 and hoping to get some input from people more experienced with these machines.

Here’s what’s happening:

• I’m seeing white speckles in the Cyan, Magenta, and Yellow full-bleed test prints.
• The Black (K) channel does not have speckles, but instead shows a vertical line running through the middle of the print.
• This is visible even on solid fills and affects production-quality output.
• I’m printing on 80lb digital cover gloss, and the issue persists across different files and runs.

I haven’t replaced any parts yet. I do have a tech involved, but he’s not very familiar with Canon machines and wants to diagnose the issue properly before swapping components.

I'm reaching out to see if anyone can suggest which parts we should start inspecting or replacing to fix or isolate the issue. Possible culprits we’ve considered include:

• Drums (CMY only?)
• Transfer belt or unit?
• Developer units?
• Fuser?
• Other suggestions?

I've attached images of both the final poster and the individual CMYK prints for reference. Any help narrowing this down would be greatly appreciated!

Thanks so much in advance.




IMG_3543.jpg IMG_3544.jpg IMG_3542.jpg IMG_3541.jpg IMG_3548.jpg IMG_3545.jpg IMG_3547.jpg IMG_3546.jpg

[122342]

White dots are the result of a worn transfer belt. When you remove transfer belt you will see those dots on the belt. Also check lifetime of outer transfer roller. Check magnet roller on Bk developing unit for clogging, that can be result of white line on black print.

[jswole14]

White dots are the result of a worn transfer belt. When you remove transfer belt you will see those dots on the belt. Also check lifetime of outer transfer roller. Check magnet roller on Bk developing unit for clogging, that can be result of white line on black print.

I actually forgot to mention earlier — the white dots tend to show up in the same general region, but never in the same exact spot on each print. Would that still be consistent with a worn transfer belt, or does that suggest something else? We’ll check the outer transfer roller life and the magnet roller on the black unit as well, especially since I’ve also seen a faint white line on black prints.

[zoraldinho]

The white dots are the transfer belt. Sometimes it can be polished and sometimes it can't because it is baked in. The line is the drum unit, in my opinion.