Canon Pro-1 Vertical banding - Nozzle check OK except for CO

[dave_n_s]

Using HP Premium Glossy and OEM inks to get back in action after little printing (but periodic good nozzle checks) before I wheel out some large format papers, I did a nozzle check and saw a good result apart from blue blocks on the CO area, so proceeded to a test print and noted fine vertical banding in the sky running down into the light areas below.

The shot of the print is about a 50% crop.

I checked alignment and noted no issues.

No error messages and all ink quantities are good.

What is recommended please?

 

[The Hat]

What is recommended please?

Your print head is in trouble, re: (the nozzle check), so you shouldn’t be doing any serious printing until you get that sorted out first..

Please post a full nozzle check for examination, but it maybe too late to save the head from damage after outputting such a large photo print, only time will tell..

 

[Artur5]

I woudn't write off that printhead yet, @The Hat.
See that the banding isn’t limited to sky areas but it covers the whole photo. Look at the lighter parts of the house.
IMHO, none of the nozzles are clogged or damaged only, for some reason, a good amount of the chroma optimizer nozzles have been contaminated with cyan or photocyan ink. Therefore, when printing on glossy/luster media we see dark cyanish bands everyhwere the chroma is applied. If all the chroma nozzles were contaminated we'd see no banding but an uniform cyanish cast covering all the print.
That weird contamination isn’t an unknown issue. It happens now and then in my Pro10 when I leave the machine unused for some time, although the amount of cyan contamination is much lower than in the OP. nozzle check.
After a regular cleaning cycle everything goes back to normal and stays so unless I leave the machine off for a couple of weeks or more.
In my Pro-10s, I guess that the chroma opt. nozzles must be besides the cyan and, after days sitting idle, some cyan ink slowly migrates along the resting pads towards the nearby chroma nozzles, Chroma optimizer is colorless, so it only takes a very small amount of dark cyan ink to make a very noticeable effect.
Always speaking of my printer, I'd bet that it isn't a printhead problem. i.e. internal leaking between color channels. This intemitent issue has been going on for more than one year maybe and it doesn't goes worse, In fact, it never happens if I print regularly. Maybe I'm wrong and the printhead is slowly ailing.. time will tell.
In the present case,, it may be different. As you know, the Pro-1 is a very peculiar machine and we can't assume a behavior similar to a Pro-10. Sadly, that Pro-1 printhead might be dying fast, but there's hope

@dave_n_s : try to perform a regular cleaning cycle and see what the nozzle check looks after. Follow @The Hat's advice, don't print anything but nozzle checks until the problem is solved, hopefully.
Also, it might be a good idea to clean the resting pads where the printhead sits when the printer is idle, although I expect that reaching those pads will be fiddly.

 

[dave_n_s]

Thank you both for your input.

I've run a cleaning cycle, actually the two groups that included both cyans and CO and the result as you can see is unchanged.

Both cyans are fine, there's cyan on the two dark grey CO bands but not on the light grey CO bands on the nozzle check.

I'll own up to having worked in engineering on many very complex systems, but I've never had to understand how inkjet photo printers in general and this one in particular work. I'm struggling to rationalise how cyan ink could only get misapplied in this one case. If I knew the difference between the dark and light bands in the CO block in a nozzle check, that would help. It seems that it can only be an electronic command issue within the printhead. If it was a plumbing issue, it's hard to imagine how it would be that case.

Hence I'm here asking the experts.

What next please and why?

 

[The Hat]

Hence I'm here asking the experts.

The nozzle check looks in very good condition except for the CO block, I reckon you have filled the CO cartridge with cyan ink, because that’s the only way you could achieve that nozzle check, like in this Pic
I have deliberately put magenta in it,

This is what the correct nozzle print should look like, the CO block has MBK printed first as a base, so that the CO can be clearly seen.. But in your case Cyan is present..

If you have used cyan in the CO cart then there is no easy answer to your problem, except a system flush and that’s very costly on ink, because the printer will need to remove all the ink from the tubing to clear the cyan out of the lines.
O' the good new is your print head is working grand..

 

[Artur5]

You’re maybe right but I have my doubts. Dave_n_s says he uses OEM ink.
Does that means that he purchases new carts every time or that he refills them with OEM ink extracted from larger carts ?.
In the first case it’s impossible that he inserted by mistake a cyan cart in the chroma slot without triggering an error.
He mentions also periodic and good nozzle check. Nothing said about refilling lately and seeing the problem arise.

Please, Dave tell us if you use just OEM carts or you refill them.

 

[dave_n_s]

Both,

I have never refilled a cartridge. I looked into it, but found that buying large batches from folks whose printer died has kept me going at around $10 a sealed cartridge, most in sealed boxes..

So the CO cartridge came out of a sealed bag in a sealed box.

I'm with @The Hat as this looks impossible, unless I'd done something stupid (which I'm very capable of) given the rest of the nozzle check is perfect.

I've noted one possible clue - the CO and C cartridges are next to each other. Could there be a plumbing problem in the ink system? If I can easily gain access, it's going to be obvious as the amount of cyan ink in those blocks is huge.

Also is CO applied on just those two currently cyan blocks of the nozzle check?

Does the amount and pattern of cyan ink on those blocks indicate that it's getting there through the print head? Through the wrong nozzles?

A software (firmware) problem?

I've also pulled the CO cartridge and at its feed into the ink system, there is no horrible mess of cyan ink - CO is actually a very pale blue, but nothing that would provide the effect shown

I then ran another nozzle check and on the two messy cyan colored CO blocks, the ink is wet, whereas all the others feel dry to touch as soon as they come out of the printer.

Next steps please?

 

[The Hat]

've noted one possible clue - the CO and C cartridges are next to each other. Could there be a plumbing problem in the ink system? If I can easily gain access, it's going to be obvious as the amount of cyan ink in those blocks is huge.

Can I asked… Are you using OEM carts or are some of the carts aftermarket, because it’s impossible to fit an OEM cart in the wrong place, but aftermarket carts you can..

Try removing both Cyan and CO carts and clean the whole area with paper towels soaked in window cleaner best you can.. Gloves needed…

Then turn the cyan cart with the outlet facing the floor and see if it leaks, I suspect the valve on the cart to be damaged, most likely filled by previous owner. ( Pure speculation)

The CO cart may be ok but I dough it, so you will have to fit two new different carts in both those slots to get started again, but this is still not going to fix your contaminated CO channel..

If you can clean up the spilled ink and be sure the problem is resolved, then your only alternative to run a system clean, but that will use 35% of your remaining ink in all the carts..

P.S. You may have great experience in engineering, but please don’t go tinkering with this printer, it’s a proper bitch and will bite you as quick as a wink..

 

[dave_n_s]

@The Hat

Starting at the end, one thing my engineering experience has taught me is never to mess with things outside my area of knowledge without a service manual or clear direction from someone who has the appropriate knowledge.

The ink carts are all Canon OEM and received sealed at least in the inner plastic film pack. None were refilled by anyone.

It's becoming most likely that contamination is the cause - a little cyan ink has got in the CO at some point before it goes through the print head nozzle. The question is where it is happening and what I can do about it.

I did check with a bright light and a cotton wool bud / Q-Tip in the Cyan and CO cartridge locations and there is no spilled ink. Does that rule out a failed CO cartridge valve? I can certainly try the shake test over a suitable surface.

I noted the third level system clean option and decided that was perhaps worth trying for the group that contains Cyan & CO.

The question is where the contamination could be occurring given the rest of the nozzle check is good and is it perhaps a small leak over time that I can get to with expert advice and clean up?

Attacking this from a different direction, is CO used on all prints or just some types of prints or is it of marginal value in some cases? If so, can I disable CO and if so, how please? I'm a Mac / Lightroom user.

Thank you!

 

[PeterBJ]

@The Hat

Starting at the end, one thing my engineering experience has taught me is never to mess with things outside my area of knowledge without a service manual or clear direction from someone who has the appropriate knowledge....

It looks like the Pro 1 service manual can be bought here at £9.99. I don't know if the website is OK.