PRO-100 head alignment query

[paulcroft]

This morning I ran a print head alignment and, on page 2, there are thin white horizontal lines through three of the blue tests (see attached photos). There is no annotation on the printouts but comparison with the 'ink levels' dialog box suggests it was the photo cyan. My first instinct was to run a nozzle check, which I did, and it appeared faultless. So I ran another two alignment checks and the lines are now gone.

I cannot find any guidance in the manual to assist in interpreting the head check results but it's pretty obvious the horizontal streaks should not be present. Having performed manual head alignment checks in the past I understand the process but the lack of annotation is frustrating. Can anyone suggest a cause of the streaks and should I be concerned?

And, finally, can anyone explain why there is no alignment check for yellow?

 

[websnail]

My first go to would be the clear disk to the left of the paper feed... it has tiny gradiations on it and is used by the printer to track it's position as it rotates... That might have a tiny amount of dirt, dust or ink spatter on it.

That said, I believe your printer is pretty new so that seems unlikely...

I'd recommend keeping an eye on your output and see if the streaks appear again... If they do, but only when more of a particular colour is used then you might want to re-prime or replace that cartridge to see if the issue is ink flow to the printhead... Sometimes ink stavation can create a similar effect although it's more a general starvation of the entire colour rather than just a few select nozzles.

All, wild, somewhat-educated guesses so not sure how much help...

As to yellow... perhaps it's to do with the difficulty in detecting the boundaries given that it's such a bright colour?

 

[paulcroft]

Your comments are noted especially since, although the printer's just over two years old, it's not been heavily used. I will definitely continue to monitor output and will run an alignment check once every week or so to see if it recurs. Still interested in the lack of a yellow alignment check if anyone else can offer a suggestion. Just curious ...

 

[Roy Sletcher]

Your comments are noted especially since, although the printer's just over two years old, it's not been heavily used. I will definitely continue to monitor output and will run an alignment check once every week or so to see if it recurs. Still interested in the lack of a yellow alignment check if anyone else can offer a suggestion. Just curious ...

I have printouts of head alignments for my Pro 100 going back to July 2013.
Non of them show a yellow ink on either page.
I am guessing that as long as you have clean nozzle check all is well.

rs

 

[mikling]

Take a look at some of the gray patterns. Now let's take a guess at what colors are there to create those grays. I know you have the answer. Now think about what an alignment does and is it a relative alignment or absolute. Do we need absolute positioning? How does an inkjet printer work? Now think where Yellow would fit in there.
Just a little further thinking and the answer will pop out. It's getting a little boring here and this should get some juices flowing.

The gap is likely something under the nozzle plate that has been cleared. To notice that large a gap multiple nozzles were not firing...leading one to suspect a fleck of dust or something physical. It can happen. If you want to reassure yourself, pop the head out and inspect but there goes the head alignment.

 

[paulcroft]

Take a look at some of the gray patterns. Now let's take a guess at what colors are there to create those grays. I know you have the answer. Now think about what an alignment does and is it a relative alignment or absolute. Do we need absolute positioning? How does an inkjet printer work? Now think where Yellow would fit in there.
Just a little further thinking and the answer will pop out. It's getting a little boring here and this should get some juices flowing.

The gap is likely something under the nozzle plate that has been cleared. To notice that large a gap multiple nozzles were not firing...leading one to suspect a fleck of dust or something physical. It can happen. If you want to reassure yourself, pop the head out and inspect but there goes the head alignment.

Are you saying that yellow is used to create different shades of grey?

I like the 'fleck of dust which has now gone' theory and, if that's so, taking the head out now will be too late to reveal anything (since the line's now gone) but I may well have a look if it recurs.

 

[mikling]

https://en.wikipedia.org/wiki/CMYK_color_model

Yellow is certainly used.

Dots are placed and as long as they are all spaced relative to each other, that is pretty much all that counts. So if the world rotates all relative to yellow, and a yellow reference is made by getting a gray pattern correct, then the calculations to adjust all the other channels can be made.
Let's think about it another way. Three persons have to get together and they need to know how to navigate to do that. These persons are CMY. How do they go about accomplishing this?, does each send out a scout and all try to move or does one stay put and two others send scouts out.

 

[paulcroft]

https://en.wikipedia.org/wiki/CMYK_color_model

Yellow is certainly used.

Dots are placed and as long as they are all spaced relative to each other, that is pretty much all that counts. So if the world rotates all relative to yellow, and a yellow reference is made by getting a gray pattern correct, then the calculations to adjust all the other channels can be made.
Let's think about it another way. Three persons have to get together and they need to know how to navigate to do that. These persons are CMY. How do they go about accomplishing this?, does each send out a scout and all try to move or does one stay put and two others send scouts out.

Thanks for the link and the explanation, that helps make sense of what's going on.