sudden lack of gray in print

[jjohnl]

I've been printing a lot the last few days, all photos with a lot of gray in them. I printed an 8.5x11 about 15 minutes ago and it looked great. I took a few minutes to decide which one to print next (I've got a group that I'm working on.), set it up in the edit program, printed it and it was a mess! I did a nozzle check, and there was absolute nothing from the gray cart. Not one single line of gray. There's plenty of ink in the cart, both the reservoir and the sponge, and the "outlet sponge" is wet.
I'm using a Pro100 with Precision Color ink. All my carts have over time changed over to CLI-8 except for the gray, which is still CLI-42.
I can change the cart, and I can change the head, but I'm don't have another clean cart ready, and I'm just mystified as to how it could go from printing fine to absolutely NO gray ink that quickly. Any ideas?
Thanks

 

[stratman]

Even if you are using an OEM Canon Gray cartridge that is using OEM ink and never been refilled or altered in anyway, there can still be ink flow or starvation problems. Such a fast time till the problem occurs - 15 minutes since the last normal print out of Gray - could mean an electrical failure of the print head.

It would be good for us to see your nozzle check. Please crop the image so that just the printed area is saved and then post.

The first thing is to not print anything but nozzle checks until the situation is resolved or you might risk burning out the nozzles irreversibly. The second thing is to try a known working or new ink cartridge, preferably a Canon.

Report back your finding and a cropped image of your nozzle checks before and after the new cartridge test.

 

[jjohnl]

Well, it's still weird!
I did another nozzle check after I got your reply (30mins after my initial nozzle check) and it looked the same: no gray at all. This is image #2.
So I put in an OEM cart and did nozzle check #3: still no gray. Did a cleaning and nozzle check and everything looked right this time. #4
Took the OEM cart out and put my original cart back and did nozzle check #5: everything still looked good. Immediately did 3 more nozzle checks but only uploaded #6 because they all looked good.
Three hours later, did another nozzle check and everything still looked good. Then I made the print I was trying to make when the gray disappeared and it's fine.

So obviously the cleaning did it but why would it be all or nothing? No streaks, no lines. Then after a cleaning it looks fine.

 

[stratman]

Is that the proper color for the Gray? It seems to have a slight tinge of Magenta to it on my monitor. If it is the proper color then read on.

It could be the affected cartridge has poor ink flow due to contamination, some irregularity in manufacturing or a lack of air flow to allow for equilibrium of pressure inside the cartridge as ink is used up.

Recently, someone on the forum (?) noticed they had not removed all the packaging wrap over the air vent on top of an OEM cartridge that allows for this pressure equilibrium. Without that air flow, ink stops flowing. Check the cartridge to see if the air vent is blocked and remedy if it is. A similar situation occurs with refilling if the refilled ink gets into the air maze and blocks air flow. Removing the ink resolves the block.

When you put in a new cartridge the printer should prime the print head with a new or replacement cartridge ink purge in order to establish a positive ink link between nozzle and the channels in the print head. You do not want air bubbles in the channels.

Now you reinstall the questionable cartridge and do some nozzle checks and it works. Part of the reason is that there still is ink in the print head channels, so things may appear OK for a while.

The real stress test is a print job that needs a more ink than what is in reserve in the ink channels. It needs ink flowing from the cartridge. As long as you do not exceed the amount of residual ink in the print head, and whatever may be sucked out of the cartridge, then all seems well with the printing.

To further complicate things, a cartridge that has ink flow problems may seem to work after a rest. This may be because there is time for ink to be wicked through the sponge towards the ink exit port. In his case, there will be ink flowing from the cartridge for a limited time until ink is no longer available and another rest period is needed for ink to wick down the sponge again. Flushing and refilling the cartridge may solve this issue.

Since you are using OEM Canon cartridges and NOT refilling, you might consider that you have a bad cartridge, no use it again and return for refund or exchange (if possible). If your printer is under warranty then call Canon Tech Support. They can be quite responsive in these situation as long as you've not refilled or used third party cartridges. I once had a defective chip on a new cartridge and they sent me a new one overnight.

 

[jjohnl]

No, actually I am refilling; as I said in the first post, I use PC inks and all my carts except for the gray one are actually CLI-8s.
I had already thought of plastic wrap possibly blocking the vent and checked it already; nothing there.

You bring up a couple interesting points:
1) As far as the color of the gray swatch, I sort of see the magenta tinge and PM sits right next to Gray. However, looking at the head where the PM cart sits, there is no sign of leakage. Also the prints I'm working on are almost all gray/black and I don't see magenta in them. (One is attached below.)
2) Speaking of how much gray/black is in these prints, you mentioned the factors of ink remaining in the ink channels. I have absolutely no idea how much that would be or whether or not these prints should extract it all, but there's an awful lot of gray in this image. Do you think that printing this at 8.5x11 (+/-) could extract it all? (And yes, that's an isolated red-magenta area in the middle of all that gray; it's supposed to look that way.)

But you know, if any of these possibilities were the culprit, wouldn't you expect to see something in the gray swatch? Because there is nothing there that I can see. And it went from a perfect print to no gray in the nozzle check, and then after the cleaning it went back to perfect. There was no in-between like I would expect if there were ink starvation. It seems like your initial thought about the electrical problem in the head makes more sense. Maybe something loose?

Edit: After posting this I printed 2 more prints in rapid succession, each one having less red area and more gray than the one I attached. I wanted to see if I could induce gray starvation. They both printed fine.

View attachment 7600

 

[The Hat]

@jjohnl, I was very curious about your nozzle check, apart from the GY Grey looking like it’s got some Magenta in it, more worrying were your M Magenta and C Cyan, if you look closely the PM Magenta and PC Cyan are the same colours.

I wonder, have you mixed up the four colours ?, see below I have reversed a section of the C Cyan and PM Magenta and placed them on top of each other, there is no difference in them...
P.S. I wouldn’t use the Grey cartridge in the printer again, without first purging, and fixing up the mistakes

.....

 

[stratman]

Do you think that printing this at 8.5x11 (+/-) could extract it all?

Most likely, seems reasonable.

I think @The Hat has hit on a good point in that your Magenta and Photo Magenta appear similar, as if you refilled each cartridge with the same Magenta ink. Without measuring the colors to see if they are the exact same, a darker Photo Magenta could be caused by cross-contamination from the Gray cartridge, which would also explain the Magenta tinge in he Gray nozzle check swath. If the Photo Magenta is slightly paler in color to the measurement of Magenta it could still mean you refilled the PM cartridge with full on Magenta and that there is dilution of Magenta ink with residual Photo Magenta ink still in the PM cartridge.

Using Windows Paint, since all windows users have this, and its eyedropper tool to select the color of each nozzle check swath and then looking at the characteristics of that color in the Edit Colors selection, the PM ink is very close to the M, with all measurements of PM slightly less than that for M. I think this can be explained by dilutional factor. Cheers to The Hat.

You can either flush and refill the PM or use up the current fill of your PM and then begin refilling with PM ink as you usually would. It's up to you and your tolerance for color fidelity.

 

[jjohnl]

No, the apparent similarity between M/PM and C/PC is likely due to the process of scanning, converting to jpg, putting online, etc. In person the difference is obvious. They're close, of course, but different.
My method for refilling carts is extremely time-consuming but eliminates the possibility of using the wrong color: only 1 cart and 1 bottle of ink allowed in the "refilling room" at one time, and I check the labels over and over during the process. I really am border-line paranoid when it comes to that.
And, of course, the bottom line is that the colors in my prints (and the standardized printer test images that you find online) look good. It's just a little disconcerting when one color suddenly stops printing at all. Because of the way that was so sudden, if it happens again I think I'll swap the head out.
Thanks

 

[PeterBJ]

In the nozzle check C and PC should have same colour strength and so should M and PM. See this post. So I think no errors have been made during refill.

 

[jjohnl]

Another thing that has to be considered when looking at the nozzle check is that it shouldn't necessarily look like a nozzle check done using OEM inks, since these are Precision Color inks. Even though you "should" get the same results when you look at a printed image, the individual colors don't necessarily have to look the same. When I was using OCP inks (in 2014) they had to reformulate their red because it got too expensive, and changing the red required them to change their yellow and cyan also. So none of them looked like the OEM inks but when combined in the printer they did the job.