MP830 prints with equally spaced horizontal lines

[phreez]

Can someone shed some light on a problem I am having with my canon MP830? Every time I print an image, I get these equally spaced horizontal lines in exactly the same location. Text prints fine. I have tried doing the deep cleaning, and even cleaning the print head with no affect. Also tried manual alignment. The nozzle check pattern appears fine. Attached are a printed picture as well as the nozzle check pattern. I even tried printing a black and white gradient picture I found on google images and it had the lines as well, although they were really hard to see on the solid black part. I initially thought this was a print head problem, but it doesn't seem to have anything to do with a clogged nozzle or streaking. Any help is greatly appreciated...thanks!

 

[Grandad35]

Only 1/2 of the nozzles are firing on the bottom half of your Cyan test. To see this better, rescan the same print at a high resolution (say 4800 or 9600 dpi), selecting a small area near the center of the cyan check, making sure to get some of each of the light and dark areas. My guess is that you will be missing 1/2 of the ink dots on the bottom half.

Unfortunately, this is usually an electrical problem in the print head that cannot be repaired. If the printer is under warranty, contact Canon for a free replacement head.

BTW - are you printing on Photo paper? Usually, this type of problem isn't as apparent on photo paper because the paper only advances about 1/8 of the print head width for each pass, so things tend to average out (but the prints will probably have a red color cast due to the missing cyan).

 

[phreez]

Thanks so much for your reply. It is out of warranty, do you think just a new print head would fix it? Or do you think it would be something internal to the printer? I tried rescanning a small area at 9600 dpi and am not sure if I am seeing the missing dots, probably don't know what I am looking for. Attached is a small area between the light and dark cyan

Also, no photo paper, just regular. This is just really annoying when printing any image, like webpages, etc if I want to show it to anyone.

 

[SpideRMaN]

Once I had a similar problem, I solved it by removing the printhead and cleaned it manually and cleaned the printhead contacts (both on the printhead and the printer) I don't know which one was the problem cos I did both at the same time

If it's an electrical problem then it's a bit risky to replace the head cos if the problem is the printer then you can kill the new printhead as soon as you install it

 

[ghwellsjr]

Usually, this type of electrical problem is just in the print head but you shouldn't put someone else's print head in your printer or put your print head in someone else's printer, just to be on the safe side.

 

[Grandad35]

phreez,

Thanks for the detailed scan. What is VERY interesting is that all of your nozzles are printing, but the ones on the bottom apparently just have smaller ink drops than the ones at the top. It would be tempting to guess that the 1 pl nozzles are being fired instead of the 5 pl nozzles in this area, but since the bottom is darker than the "light cyan" nozzle check, that can't be the case. This failure is almost certainly inside the electronics in the print head. When printing on plain paper, there isn't nearly as much randomization, so you get banding.

The odds are that a new print head will fix the problem. I agree with ghwellsjr that it is best to avoid testing questionable print heads in another printer.

 

[ghwellsjr]

The normal nozzle check for the typical Canon printer puts four dots down on top of each other. When the print head is aligned, you cannot tell that each of those dots is made from four droplets from four different nozzles. See this post for a discussion of this issue.

If you do a manual alignment on your printer and place all the settings at the maximum negative value, your dots will separate into individual dots and you will see that there are four in the upper part and two in the lower part (or maybe with your printer it is two and one). Try also the maximum positive value.

The conclusion remains, unless you can fix this by cleaning the contacts on the back of your print head and on the carriage where they mate, you will need a new print head.

 

[phreez]

Thanks everyone! I will try cleaning it, but looks like I will be buying a new print head and I will let you know how that goes. This is a pretty interesting problem to me and I learned a lot about inkjets from it so much thanks.

 

[phreez]

I got a new print head and it fixed all problems! Thanks again for all the help on this forum, it made it much easier to justify buying a new print head. Thanks!

 

[ghwellsjr]

You're welcome.

BUT---We would like (in the interest of science) to learn the results of the test I proposed in post #7.