MX925 - Missing bands on the nozzle check pattern

[stratman]

Ink is OEM carts refilled with Octoink

High or photo paper settings give out weird colours.

Is it possible your ink is an incorrect match for your printer or is old or contaminated?

Just tried some new carts.

Do you mean just purchased new OEM cartridges or something else?

 

[stratman]

The new work around is to print plain paper in standard settings. High or photo paper settings give out weird colours.

Very interesting and worth exploring further, at least to me.

If the ink you are using is appropriate and has worked for you well in the recent past then the "weird colours" effect could be due to what is causing the missing nozzle swaths. Those missing swaths represents gradations of nozzle firing for that color. Using a magnifying glass you can see different densities (distance between) of dots of the color.

A set of nozzles on the Canon thermal print head can only produces one droplet size but is able to control placement of the dots closer or farther apart to give different/improved appearance of the image. (Epson's piezoelectric print head can make different droplet sizes.)

If your print head is unable to fire specific Cyan and Magenta nozzles at different density/spacing then the perception of color may be altered.

My guess is that the use of your print head nozzles to lay down different densities of color dots in High and Photo Paper settings relies more heavily upon your failed nozzle swaths than in Standard Plain Paper setting and thus may be the cause of your perception of altered colors.

Hopefully the experts in this area will post.

Since this is a just purchased print head, have you contacted the seller about replacement/refund?

 

[def3]

Have you tried to install back the first printhead with faulty pigment black, as wisely advised by @stratman ?

I don't have it anymore, threw it out.

CRC-Tasktron has got back to me and confirmed most of yur suspicions of it being an issue with the main board.

They've given me a repair price, unfortunately it doesn't make economic sense to go ahead with it.

I'll use up the remaining ink I have and move over to a printer.

Thank you all for your help.

 

[stratman]

CRC-Tasktron has got back to me and confirmed most of yur suspicions of it being an issue with the main board.

You've had different problems with different print heads. It is peculiar that your logic assay board would suddenly develop an issue completely different without some antecedent other than the previous print head's warped nozzles, which, as far as I have read, is not thought to be an issue with the logic assay board.

Warped nozzles is a physical manifestation of too much heat at the nozzles, typically seen on this forum when aftermarket inks are used, that may or may not be more likely to occur due to a design or manufacturing alteration compared to past print head models.

I guess anything is possible but this seems a little fishy to me if you've never had missing ink on nozzle checks and then all of a sudden a "new" print head displays this issue from the beginning.

In other words, CRC-Tasktron may be passing the buck... back to you.

 

[def3]

Update:

Decided to buy the logic board (QM7-2696-000) from CRC-Tasktron.

Followed a printer teardown on youtube and swapped it out.

Printer is now running like new.

I only decided to do this after I had already spent money on the new head and there was no stock for the printers I liked.