shaded print of black color print on Canon IP7240

[Hamid]

hi guys,
happy to find this forum, while searching for my printer issue.
i'm using an IP7240 for about two year using for printing my personal photos.
after replacing some original cartirdges, i started to refill them with Inktec ink. as i feared to clog head nozzles i diluted the ink for about 7-8% with inktec Solvent. after a while i found out that my black color fades. i mean when ever printer uses this black color (for example printing water mark on my photos) a shade is appear around the printed alphabet. also if you look at below nozzle check some sort of ink diffusion is clearly visible.



first i thought it is because of too much dilution on black ink, but i used original cartridge and do several nozzle cleaning and also some prints but still the same result.

then i tried aligning the head and see some interesting line disorder at the end. (below picture)


comparing to the alignment pint i've done while setupping the printer (below image), these lines were straight.



also printing the alignment value as below, every thing seems to be fine.



can any one help me figure out what is the problem?

sorry i have no scanner and use my phone to take some photo of the printer results.

 

[Ink stained Fingers]

which inks did you dilute - all of them or only the black inks ? Dye inks can bleed through regular copy paper, that's nothing special, the dye black BK more than the PGBK which carries pigments remaining more on the paper surface. Do you have a problem with edge sharpness on letters ? You may in that case clean the coding strip, a small gray plastic band across the print range in the back, passing through a sensor on the back side of the printhead carriage. Use some kitchen paper or Q-tips like this
https://www.printerknowledge.com/th...ion-and-submissions.9937/page-107#post-107087
and wipe along this coding strip on both sides, soaked with a window cleaner.
Do you have a chance to get any closer with your phone ? with a macro mode ?
The printhead alignment can only be done when the nozzle check is in good condition .

 

[PeterBJ]

By zooming in on the first picture I think I can see some fuzziness in the two vertical bars surrounding the "BK" letters. This is a print head damage probably caused by an ink unsuitable for the print head. Sadly the print heads of the PGI-x50/CLI-x51 cartridge generation seem to be very fragile in this respect, there have been more reports of this kind of failure. Also PGBK can be affected and show double contour printing of the nozzles at the centre of the test stripe in the nozzle check. Only a new print head can correct this failure, but is it worth it as the print head might be more expensive than a new printer?

See this post and some following posts for more info about this print head failure.

 

[Hamid]

i diluted all the inks but i for the PGBK i diluted for 3% only.
i just tested the original PGBK, but problem still exists.

i cleaned the coding strip also and checked it again, i think the miss alignment is got better. but the sharpness on the edges still is a problem.
while cleaning the strip i saw lots of fresh int in here below. is it the purge tank? is it normal?



i did a more clear photo of nozzle check.



also i did the nozzle check on different papers but with the same result.

 

[PeterBJ]

The quality of your photo is OK but sadly it clearly shows that the dye/photo black nozzles have failed. Only a new print head can correct this error. No amount of cleaning either inside or outside the printer will do any good.

The purge unit looks perfectly normal to me, it quickly gets stained from ink in use. Here is a photo from the multifunctional MG5450 that uses a printer part that is similar to the iP7240:

 

[Hamid]

By zooming in on the first picture I think I can see some fuzziness in the two vertical bars surrounding the "BK" letters. This is a print head damage probably caused by an ink unsuitable for the print head. Sadly the print heads of the PGI-x50/CLI-x51 cartridge generation seem to be very fragile in this respect, there have been more reports of this kind of failure. Also PGBK can be affected and show double contour printing of the nozzles at the centre of the test stripe in the nozzle check. Only a new print head can correct this failure, but is it worth it as the print head might be more expensive than a new printer?

See this post and some following posts for more info about this print head failure.

thanks alot.
do you believe the problem will got worth or i can use the printer with this problem. as you can see less than a thousand print is done.

 

[Ink stained Fingers]

I don't think diluting ink as you are doing it does not have the expected effect. The ink is a mix of about 5-10% of the dye color and the rest, the solvent is a mix of water and some glycoles, and if you add a few % more of a solvent it does not change the ink to solvent ratio very much, clogging is a more complex process.

 

[Hamid]

thanks every body.
i reviewed the discussion under the other topic too.
despite of every thing, it seems that under some circumstances every thing is OK and the print quality is superb.
finally, it seems there is nothing i can do.

did you mention such condition on EPSON printers? most of people believe their print head better response to refiling and third party inks. but i think the CANON quality is better at last.

 

[Ink stained Fingers]

it is just not possible to make a general statement that Epson printers are better - or not - than Canon printers, you need to define the criteria and have or get sufficient data to decide that. There are just too many parameters and personal preferences as well for such a comment