What does this scan of my Canon i865 nozzle check indicate?

[jackson]

I printed a sheet of black text using the 'Photo Paper Pro' setting and the text was printed in perfect black. Hmm, any recommendations on what printer I should get next. :/

I think Defcon is right and Canon is not.
If the 'N' block is supposed to be photo black (according to Canon) then something is telling the printhead to use Yellow and Cyan in error.
But it sure looks like it's supposed to be a composite of CYM which means the magenta is missing.
I printed a yellow block then overlayed part with cyan.The result is the same as your image.
So I conclude that some magenta nozzles are blocked..just as Defcon alluded to.

Here is a partial extended nozzle check of a Canon i850 with a bad head.
It prints poorly set for plain paper, but is quite acceptable on plain paper if the setting is changed to 'Photo'.
Taking the Magenta as the good nozzle, compare to the whole section missing from the cyan.

 

[Defcon2k]

Wam7, if you want to check the nozzles, try an extended nozzle check in the service mode of the printer. The regular check is a little bit hard to interpret sometimes. Look at this picture: Even if 50% of all cyan and magenta nozzles are missing, the nozzle check looks not that bad.

A) Entering service mode:
- make sure the printer is turned off.
- press and hold the [resume] button, and then press and hold the [power] button. (Now you are holding both buttons down)
- release the [resume] button (but do not take the finger off the power button)
- press 2x [resume]
- release the [power] button

B) Functions available in service mode:
Once you have entered the service mode, you can select one of the functions mentioned below by pressing the resume button the specified number of times and confirm that selection by pressing the power button. (btw: to give you some optical feedback, the indicator LED toggles between orange and green each time the resume button is pressed.)

- 1x [resume], then [power]: extended nozzle check
- 2x [resume], then [power]: EEPROM information print
- and many more, which could mess up your printer if you don't know what you're doing.

You can leave service mode by pressing [power] without pressing resume before.

 

[ghwellsjr]

This post might provide a clue as to what might be happening here:

http://www.nifty-stuff.com/forum/viewtopic.php?pid=10624#p10624

You may have to study the posts before and after to get a clear understanding of what is going on, but, basically, it appears that the nozzle check uses just one of the two sets of nozzles for cyan and/or magenta when printing the blocks and characters on the left side. I think this points to one of the magenta sets of nozzles being totally nonfunctional and it is probably an electrical problem in the head or the printer.

It could be a faulty contact or it could be a defective head but it could also be a bad electrical driver in the printer. If you're lucky, it will be a faulty contact which you could probably fix, but if it is a defect in the printer or the head, that defect could actually have damaged whatever it is connected to, which in turn could cause more damage.

For example, let's say one set of your magenta nozzles in your head developed a short circuit. It's possible that the short could burn out the driver in the printer. Suppose you were to take your head to another printer to see if it works and it burns that printer out. Or suppose the electrical driver in the printer developed a fault which burned out the set of nozzles in the print head. Clearly, putting a working print head into that printer would not be wise. However, I have no ideal if the electrical drivers for the nozzles exist in the printer or in the head itself, so there may not be any risk at all, but you should assume full responsibility for any experiments you make.

Having said that, in my opinion, there is probably less risk of putting a new printhead in your printer than of putting your apparently bad head into another printer. I wish you good luck.

 

[Defcon2k]

Here's a picture of another i865 with a strange behaviour: As you can see, half of one set of the big cyan nozzles doesn't work anymore. Therefore, there are dark red stripes in the left black bars and in the M and N parts of the nozzle check.


Btw: I think it's an electronic problem in this printer, although I don't understand how this can be. If this printer is like the iP4200, there seem to be only 4 head data channels for cyan:
C1 (HD2_C1)
SC1 (HD3_SC1)
SC2 (HD12_SC2)
C2 (HD13_C2)

This would make sense since there are 4 rows of nozzles (2 big, 2 small), but how can only half of a row be missing?

 

[ghwellsjr]

It's possible that the addressing of the nozzles is not working with the highest order bit. Maybe the bottom half of the large nozzle rows are printing on the top half. If you could print the nozzle check pattern on glossy photo paper and look at it under magnification, you might see three times as many dots in the upper half as you see in the lower half. If you only see twice as many, this would indicate that the nozzles aren't firing at all. Either way, it does sound like an electrical problem.

 

[Defcon2k]

Good idea! I'd do it if it was my printer, but I think the owner of it won't bother to... I was just wondering about it. But thanks anyway!

 

[jackson]

Here's a picture of another i865 with a strange behaviour: As you can see, half of one set of the big cyan nozzles doesn't work anymore. Therefore, there are dark red stripes in the left black bars and in the M and N parts of the nozzle check.


Btw: I think it's an electronic problem in this printer, although I don't understand how this can be. If this printer is like the iP4200, there seem to be only 4 head data channels for cyan:
C1 (HD2_C1)
SC1 (HD3_SC1)
SC2 (HD12_SC2)
C2 (HD13_C2)

This would make sense since there are 4 rows of nozzles (2 big, 2 small), but how can only half of a row be missing?

I have a Canon I850 which displays the same symptoms with Cyan.
'Standard' printing is mediocre;'High' printing is good.

 

[Trigger 37]

Hello,

I believe that "Canon Support" told you wrong. Those M & N patterns are supposed to be black which is created by printing CMY in equal parts. You are getting green because your Magenta print head is clogged, or the ink tank has been refilled so many times that it is clogged and not really supplying ink even though it looks full. I know this because I had the same problem. The little bars to the left of the Cyan PC, Magenta, PM, and Yellow are also supposed to be light and dark shades of gray produced by percentages of all the three colors. Yours come out all various shades of green, which is the same as blocks M & N. Blue and Yellow make green and even though you are printing some magenta it is not sufficient. Do a deep cleaning on colors, then print a lot of magenta test patterns. As a test if I were you I would also try a different Magenta ink tank, and/or clean the printhead in your sink.

 

[Trigger 37]

It has been 6 days since I post my suggestions. Either you died or lost interest in a solution. It would be nice to hear back from you.

 

[Wam7]

Sorry guys, I have been on the road for a while (musician). Thanks for the help and pointers.

@Trigger 37
I totally agree with you about Canon "Support". I printed out the test pattern with just the magenta ink in the printhead not expecting it to print at all BUT it printed fine. I tried this with all the other single inks and they all printed their colour

I thoroughly cleaned out the printhead on more than 1 occasion so I think there is something seriously wrong with the printhead if it prints magenta on it's own but doesn't want to know when dark shades are needed. In the end I just ordered another i865 printhead for 41 inc vat.