CANON MG7520 GRIDLINES,LETTERS AND BARCODES MISALIGNED

[FAUSTOCG]

Hi I need your help, I hope you can give me a hand to fix my printer since canon support was not able to. I removed the printhead from my canon mg7520 to flush it and after I put it back my printer started printing letters, bars and grids wrong I have attached a pdf copy of my printer´s "print nozzles test pattern" so you can see what the problem is. Bellow are the steps I took to remove the print head I know step 5 is the cause because I did a test page before and the letterS and grid printed OK.





1.- Dida a print nozzle check pattern (printed 100% clear and sharp but colors where missing/clogged)

2.- Open the display door of my printer, waited for the printhead/inktanks cart to move to the center

3.- Removed the ink tanks

4.- Open the small black door with the white CANON logo

5.- Hand push the headprint/inktank cart to the right just enough to be able to pull the lock to free the print head.

6.- Flushed the printhead

7.- Did al reverse steps to put it back together

8.- Printed a nozzle check pattern all black and color where back working but letters and grid got fuzzy,distorted, misalligned.

(Printer was ON all the time all the steps)



Best regards

 

[stratman]

An unusual nozzle check. I am not sure what your printer's nozzle check should look like but it appears you regained all your colors and now have some "double-vision" from some of the PGBK pigment black ink cartridge print out portions.

The patchy/blocky look to the color horizontal bars may just be scanner or JPG creation artifact as might be the alternating black/white stripes within the BK horizontal bar. If the original print does not contain these artifacts then no problem and you can chalk it up to scanning or JPG image creation.

canon support was not able to.

Was is that Canon would not help at all or that what Canon suggested did not work? If the latter then what was it Canon suggested trying?

5.- Hand push the headprint/inktank cart to the right just enough to be able to pull the lock to free the print head.

I have not heard people needing to push anything on the carriage in order to get the print head out UNLESS there is some other issue occurring. Why did you have to push on the print head carriage?

7.- Did al reverse steps to put it back together

For completeness, is the print head seated and locked down properly?

8.- Printed a nozzle check pattern all black and color where back working but letters and grid got fuzzy,distorted, misalligned.

Have you tried performing a print head alignment? This is done via the printer's software Properties function typically.

I hope this will be simple to correct, like with a print head alignment, and not an electrical malfunction such as replacing the print head after flushing while it was still wet causing a short.

 

[PeterBJ]

I remember having seen a similar nozzle check somewhere. I didn't find it on this forum, but I found this at druckerchannel.de. Here is a translation to English. Notice the answer #2 by Powdi that the defect is overheated and warped PGBK nozzles caused by an unsuitable ink with wrong cooling properties. So @FAUSTOCG which ink/cartridges do you use?

 

[The Hat]

I would also try giving the timing strip a clean to see if that would help..

 

[stratman]

Notice the answer #2 by Powdi that the defect is overheated and warped PGBK nozzles caused by an unsuitable ink with wrong cooling properties.

Nice find, Peter!

 

[FAUSTOCG]

An unusual nozzle check. I am not sure what your printer's nozzle check should look like but it appears you regained all your colors and now have some "double-vision" from some of the PGBK pigment black ink cartridge print out portions.

The patchy/blocky look to the color horizontal bars may just be scanner or JPG creation artifact as might be the alternating black/white stripes within the BK horizontal bar. If the original print does not contain these artifacts then no problem and you can chalk it up to scanning or JPG image creation.
Yes, color are with no artifacts but black letters and grids printed like "double vision"

Was is that Canon would not help at all or that what Canon suggested did not work? If the latter then what was it Canon suggested trying?
What canon suggested did not work (manual and autohead aligment) they want to ship me refurbished unit to replace mine but mine are almost new like 4 months with little use.


I have not heard people needing to push anything on the carriage in order to get the print head out UNLESS there is some other issue occurring. Why did you have to push on the print head carriage?
Besides the top lcd cover and the front cover tray to open there is a small door with CANON logo that has to be open in order for me to pull a locking bar so I can pull the printhead out but this is a 6 ink system so 1 ink is a little bit to my left so I pushed to the right a little bit to pull the lock and free the printhead.

For completeness, is the print head seated and locked down properly? Yes it is.


Have you tried performing a print head alignment? This is done via the printer's software Properties function typically. at first several times and then canon tech support ask to do that and have done it again and still the same problem.

I hope this will be simple to correct, like with a print head alignment, and not an electrical malfunction such as replacing the print head after flushing while it was still wet causing a short.

I own 2 MG7520 and both are doing the same thing I printed the "nozzle aligment test" from the second printer and printed with missing colors but black letters and gridlines 100% right, after I removed the printhead (this printhead I did not flush it) I reinstalled the printhead and now black letters and gridlines showed after printing the nozzle aligment test, so now both printers are not working right.

 

[FAUSTOCG]

I remember having seen a similar nozzle check somewhere. I didn't find it on this forum, but I found this at druckerchannel.de. Here is a translation to English. Notice the answer #2 by Powdi that the defect is overheated and warped PGBK nozzles caused by an unsuitable ink with wrong cooling properties. So @FAUSTOCG which ink/cartridges do you use?

I have been using refillable ink kits from amazon, but the problem started after flushing or removing the printhead on both printers, first printer was ok black letters and grids ok but colors missing removed the printhead and flushit reinstalled and problems showed up, second printer only remove the head installed the printhead from the first printer to see if the problem was the print head or the printer itself results where the same so a reinstalled the original printhead of the second printer and now problems showed up on the second printer too, this printhead I did not flush it at all.

I have seen the links you posted and as far as I can see they are the same as mine. Do you think theres is a fix or should I ask for a warranty replacement.

In the future what would be the right way for removing and cleaning/unclogging the printhead from a canon pixma MG7520 printer, would it be to much if I ask for a tutorial with pictures.

Thank you very much guys for all your help.

 

[stratman]

If you are under warranty then call Canon technical service and use the warranty. If you tell Canon you have been refilling, or, if you return the printer to Canon with anything but unmolested (never refilled) OEM Canon ink cartridges then Canon may decline to honor the warranty.

It sounds like you tried using bad printer A's print head A and put it in supposedly good printer B and had the same problems with printer B. Then you put print head B back in printer B and still have the same problem in printer B.

We have heard of this kind of crossover issue where a bad print head causes a malfunction in the printer's logic assay board or vice versa, the printer's logic assay board causing a problem with the print head. It is very rare by forum member accounts. Unfortunately, these kinds of malfunctions are permanent as far as we have heard. Fixing the issue may require both a new logic assay board and print head. It could also be a problem elsewhere. Chasing down the problems you are now experiencing could become quite expensive and time consuming, especially since we have little knowledge about your specific problem.

Given the cost of a new print head and the very real possibility the new print head will either not fix things or could be permanently damaged itself by the logic assay board (or whatever), I would suggest that you get a new printer if you are no longer under warranty.

 

[The Hat]

@FAUSTOCG, It sounds like you washed the print head and didn’t thoroughly dry it before reinstalling it, and as all ready stated by @stratman that will also damage your logic board.

Then by putting that print head in the other printer it did the same thing to that one also and will continue to do that till you replace both the logic board and print head on both machines.

If you contact Canon under warrantee then don’t tell them what you did, plead ignorant and don’t offer any explanations either, tell them you don’t have a clue what happened.

Please report back on your progress..

 

[FAUSTOCG]

Hi, thank you guys I will send one back to canon the other one I think I have extended warranty by bestbuy will take it back to see if they can fix it or replace it.

Will let you know what happens