Canon i960 Banding Issue

[Grandad35]

turbguy,

You said that all of the extended nozzle check grid patterns are flawless. The PM and PC patterns (in the middle) are difficult to see clearly on your image, but they dont look good. Do they look as good on the original print as the other grid patterns?

Looking closely at the solid color gradients, I see dark outlines on most of the colors, with light bands just inside of the dark bands on the Magenta gradients. Are these real, or are they just sharpening halos where your scanner has applied a USM to the image?

When printing photos, the paper normally advances 1/8 of the print head width (the width of the grid pattern on the nozzle check) for each pass of the print head. When you print, how far does the paper advance with each pass of the print head? There are other print modes that advance the paper by bigger steps (and therefore print more quickly), but at the expense of the print quality. Could your printer have been accidentally put into a low quality mode?

 

[turbguy]

OK. here's the best I can do to shgow you the extended nozzle check patterns. You can see that one nozzle on the Magenta check appears missing. All else looks OK (excuse the enhancement artifacts).

PLEASE NOTE THE RED ANNOTATED AREAS OF THE BLACK NOZZLES. If I understand past posts correctly, succesive horizontal lines-nozzles should be incrementing DOWN after each vertical line. At the red circled areas, latter lines are distinctly printed ABOVE the prior line. If the printing nozzles increment downward during the extended check, how do later horizontal lines, at times, end up ABOVE the prior horizontal lines?? This happens in the color areas too, but it's hard to see in the photos...

Comments??

MAGENTA PATTERN



PHOTO MAGENTA



BLACK



PHOTO CYAN



CYAN

 

[turbguy]

OOPS! Forgot the Yellow..

YELLOW

 

[turbguy]

Also, during photo printing, the paper advances about 1/8" per swipe of the head...

 

[Trigger 37]

turbguy, sorry for not responding... I've been gone for two weeks. Your test prints look very good. The mising line in the Cyan is not all that uncommon. I have seen it several times on other printers where one or two nozzles don't print. I have one now that is missing 3 lines very close together and no amount of cleaning will clear it. Must be a very small piece of contaminant right at the nozzles.

As far as the shift in the nozzle prints, where the next line is supposed to be down but is not, I have also seen that on several of my somewhat poor printhead. I have never resolved how it could happen other than a defect in mfg. process. My only suggestion is to print the pattern several times and see if the same nozzle jumps at the exact same location each time. Only other suggestion I would have would be to clean the timing strip. If you know how to get the top cover off it is easy to clean with a soft cloth and Isopropyl Alcohol. Just be very careful not clean it too much as you can scrape the tiny black lines and each one counts. If you can't get the cover off, you can get at most of it in the same way you would remove a printhead and power off the printer. Then you can move the carriage from side to side and access the timing strip one section at a time. Good luck.

 

[turbguy]

Thanx for all your help. I renewed the printhead and the pri9nter returned to it's original (exceptional!) quality. I am certain that the "misplaced" ink is the root cause for the streaking I was experiencing. Since the treaking was a sudden change in quality several months ago, it probably was not a manufacturing defect, unless it emerged after the warrantee period.....

 

[Trigger 37]

turbguy, glad to hear you got it working, but I'm not clear what you mean when you say you "renewed" the printhead. Do you mean you cleaned it or you purchased a new replacement printhead. Let us know what you did,... it will help others.

 

[turbguy]

I replaced the printhead with a new one, obtained on eBay. WORKS JUST LIKE IT USED TO NOW!!

I'd still like to know what happened to the old printhead, as it appears the nozzles are not firing correctly (nozzle check shows it upon close inspection). I guess Canon holds those cards close to their chest...