Tiny stripes on magenta (Canon MG6150)

[lbschenkel]

My MG150 ran out of ink some time ago and went unused for a while (I was busy on other things). I recently changed all the cartridges (always used original Canon ink so far) and I printed a nozzle check page. I noticed that there is a tiny white stripe on each one of the the second and third magenta bars. I thought that it could be the paper so I printed another one (in the same standard paper, it's the only one I have available in the house at the moment), and the stripes showed up again on the exact same location. I performed a cleaning (normal, not deep) and printed a third check page but they're still showing up at the same spot.



To my fellow forum members: what could be the cause and what should be my next step? Perform a deep cleaning? Auto/manual head alignment? Something else? It has been a while since I last printed a nozzle check, so this could be from before the cartridge change.

The stripes may be hard to see in the attached photo (taken with my cell phone), if desired I can later take a new better photo with my DSLR.

Any help is greatly appreciated.

 

[The Hat]

The first thing is not to panic, try printing 6 of this test sheet on plain copy paper and then run another nozzles check, chances are the tiny white stripes will be gone..

 

[lbschenkel]

OK, I printed your test sheet 4 times so far... I will post pictures later (it's late night here now, and I can't get a good photo in dim incandescent light). What happened is that I got a long stripe in the form of a line spanning *all* squares (but in the black squares the line was black and in the others white) and it was more pronounced in the first print (especially the black ones) but it got subtler in the 2nd and 3rd prints. I saw no difference between the 3rd and 4th prints. I decided to print the 4th in portrait mode just to confirm that the line was parallel to the movement of the print head, which it was.

My interpretation of this experiment so far is that the stripes happen at the exact stop where the printer printed a "row" and pulls the paper to print the next row. Maybe due to the way that my particular paper absorbs ink, for the color inks the dots were not big enough to cover the "seams" and a gap forms there, but for the black ink (since I believe the printer will use pigment black in standard paper) there is an excess of ink so I see it "blacker". Would that make sense?

In case I'm right, should I proceed the test with a different paper, more suitable for inkjets? In case I still see these gaps, would it be something that a print head alignment can fix? Canon recommends using the MP-101 paper for this purpose, at least for auto alignment.

P.S.: Let me digress a bit, how does the printer do an automatic head alignment? Does it have sensors inside the printer that check the exact reflectiveness of the Canon ink on the MP-101 paper?

 

[PeterBJ]

Instead of using a camera for the nozzle test prints, you could use the scanner in the MG6250. It can do a good scan of a nozzle check with the proper settings. This post is about using an MG5150 for scanning nozzle checks. I think the scanner in the MG5150 is the same as in your MG6250. Please upload a scan of the nozzle check.

When doing an automated print head alignment the printer prints a special pattern with rectangles.. A reflective sensor on the underside of the print head carriage can detect unevenness in the printed rectangles when the print head carriage is moved from side to side or the paper is moved back and forth. The best setting is the found by finding the least uneven rectangles.

Some say a manual print head alignment is more accurate. When doing a manual alignment you decide which rectangles are best and enter the values. Good light and a magnifier is helpful when doing a manual print head alignment.

 

[The Hat]

This test sheet was not intended to anything other than exercise all the nozzles in the print head, like a good work out, it was to help get a good flow of ink through the heads and hopefully clear any blockages that may have occurred during any down time (Idleness).

A nozzle check should provide some answers...

 

[lbschenkel]

<facepalm>... I have completely forgotten about the scanner...
I have printed a new nozzle check and scanned it. Note the small white lines on magenta.

 

[The Hat]

Looking at that nozzle check, I’d just ignore the magenta and carry on printing, if you’re worried that it might show up in a photo just switch to high quality printing, and don’t forget to print regularly, the more you print the better it will look...

 

[lbschenkel]

OK, thanks for the help.