PIXMA MX926 started printing "shadow/double" letters, some lines with blurry text, only on black ink

[echobot]

Hi All,

Well it seems that the previous unresolved threat on this subject has been locked so hopefully I can place an update here.

Please refer to the original thread here:  https://community.usa.canon.com/t5/Personal-Printers/My-printer-started-printing-quot-shadow-double-...

I have figured out what the problem is and it's 100% a fault with the large Black Pigment Ink part of the print head.  It is mechanically different to the other print head jets because it has to deal with the pigment ink.  I have the feeling that it jams up, causing this issue.

I came to this conclusion because I purchased a third MX926 which was used but in excellent condition.  It was printing perfectly for the first six months and then, as I'd guessed, it started to print double.  As it had just begun to do that, I noted that the large black ink cartridge was about 80% depleted, so I immediately removed it and put a new black cartridge in and re-primed the head again using a deep clean.

Surprisingly, the printer started to immediately print normally again.

I now print something with the large black head (pure black bold text) every second day and replace the black cartridge when it gets to about 70% depleted and so far, after another six months, it has continued to work perfectly.

I think I intervened just at the right time and I feel that as the ink thickens, it must somehow jam up the respective ink head jets.  By supplying it with fresh and less viscous ink, it obviously restored operation.  I feel that once the head is blocked, there's no restoring it.  I've tried flushing the faulty heads using every known technique, including disassembly and pressurised cleaning solutions, all to no avail.

It's 100% definitely the black pigment ink jets in the print head that is the issue and I feel that as there is no fix, Canon don't want to acknowledge it. 

Hope that helps.

[simon_pengelly]

I've struggled with the pigment nozzles (and getting black to print) on my TS6051 for years. A maintenance nozzle check printout now shows no matrix of descending lines at all. [possibly because the maintenence test print takes its setting and paper from the cassette, see below]

In common with others, I get a shadow on black text It is greyand just shifted lower, so still mostly within the letters. But now to the left!

To see if it's a problem of the cartridges moving, I jammed the cartridges with paper under the printhead end of the unit. No  improvement. I can’t think of a way of making the whole printhead/cartridge assembly more stable on its runner. Does the canonTS6051 print bi-directionally?

I use a test print that has bands of each RGB and each MCY plus one of black in each of 10,10,10; 32,32,32; 0,0,0 intensities and TEXT, each band has a text heading. Below that is a set of overlapping half-ovals of fine lines. The text and ovals have shadows.

The colour bands are perfect. As are the colour bands of the maintenance nozzle-check - even with a jeweller's loup, I can see each dot seperately. However, the bottom grey band bleeds clear dots to the left - interesting as the text shadow was below. I put a piece of sellotape over the nozzles for the pigment cartridge and text lettering still had a shadow printed below.

I printed my test sheet in landscape and the shadows on the text was then different, still printed below the letters ie towards the longer A4 side! I’ve since printed portrait and the shadow is now to the left of the text.

It is important because of the need to print out QR codes which can't be read if they are corrupted

A major problem is that there is minimal control over the printer characteristics. - especially to get black printing, I have to set it to high resolution paper to get any black printed but then can’t set it to take paper from the cassette. The maintenance test prints take paper from the cassette whatever the printer settings. It’s impossible to disable individual cartridges - eg black or pigment.

[Tiffany]

Welcome to the forum!

We appreciate your participation, though we need to let you know that your product appears to be a model that is not supported by our team here at Canon USA. While the community is welcome to chime in, the Canon Community Forum is hosted and moderated within the United States by Canon USA. We are only able to provide support for Canon products manufactured for and used within the US market.

If you live outside the United States, please click HERE and select your country to find support in your part of the world.

[simon_pengelly]

Thank you for that. I am looking for support within the Canon community and suspect that the design and construction of most Canon domestic inkjet printers have a lot in common between models (and similarities with other makes).

As quite a number of your USA customers seem to be getting similar problems to me, I thought it might be useful for them to have my experience and techniques.