Single nozzle failure IP8500 = banding?

[nertog]

Hi all!

I noticed some light banding on my IP8500 prints lately and decided to do a nozzle check. The normal nozzle check page is perfect but on the extended service check I can see 1 single nozzle of the photomagenta head refusing to work (1 little square in the grid is missing). The rest of the patterns are absolutely 100% ok.

Is it possible that the failure of 1 single nozzle is causing banding when I print in the highest quality, 8-pass mode? Or should I look more in ink feeding problems due to a bad cart? Regular and deep cleaning cycles do not resolve the problem...

FYI I'm using hobbicolors ink with original canon carts on HP advanced microporous paper.

Thanks,
Wim

 

[pharmacist]

Wim,

can you upload the scan of your nozzle check printout ? Did you execute a (deep) cleaning cycle to see if your problem went away ?

 

[nertog]

Wim,

can you upload the scan of your nozzle check printout ? Did you execute a (deep) cleaning cycle to see if your problem went away ?

I can't upload a scan at the moment (no scanner or digicam here), but I did "simulate" the problem:



This is how the photomagenta looks like. I know the IP8500 has a slightly shorter but wider grid, but I think this illustration is clear. The grids of the other colors are 100% intact.

I did several head cleanings (2 of them were deep cleaning cycles) and it didn't solve the problem. Can 1 failing nozzle cause problems like this? Even when printing on highest quality mode?

 

[ghwellsjr]

You may have two unrelated problems. It does appear that you have one damaged or at least severely clogged nozzle but as you pointed out in your first post, it is not noticeable with the regular nozzle check and shouldn't be noticeable in your printouts either.

Can you tell if your banding problem is a result of a lack of magenta, which would cause the bands to appear green or is it some other color?

I would think that a single nozzle failure would show up more in the print qualities that use fewer passes. Is it only noticeable in the highest quality that uses 8 passes?

 

[nertog]

You may have two unrelated problems. It does appear that you have one damaged or at least severely clogged nozzle but as you pointed out in your first post, it is not noticeable with the regular nozzle check and shouldn't be noticeable in your printouts either.

Can you tell if your banding problem is a result of a lack of magenta, which would cause the bands to appear green or is it some other color?

I would think that a single nozzle failure would show up more in the print qualities that use fewer passes. Is it only noticeable in the highest quality that uses 8 passes?

The banding seems to occur in all colors, but is most easily visible in blue gradients or darker areas of the picture. So at first sight the magenta doesn't seem to be involved...yesterday I tried to print a very light magenta gradient and...yep, slight banding again. I guess the banding is visible in every color.

I'll try a test in one of the lower quality modes later in the evening.

 

[ghwellsjr]

I think then, that you have two unrelated problems. Your banding is not caused by the failure of a single magenta nozzle.

One of the causes of banding is a dirty timing strip. See this post:

http://www.nifty-stuff.com/forum/viewtopic.php?pid=25544#p25544

If cleaning the timing strip does not solve your problem, it would be most helpful to see some images of the banding. You can use the image Upload link at the top of this page to post your images.

 

[nertog]

Thanks for the answers. I'll check the timing strip this evening.

I did print another normal nozzle check yesterday and when the PM is examined with a mag. glass under a bright light source I can see a very faint white line running through it. I guess this is the nozzle which is clogged or has failed.

Does it actually happen often that a nozzle resistor burns out? Or is this almost impossible? Hopefully it's just a clog...will try a total printhead cleaning later this week.

Maybe I'm expecting a bit too much from inkjet printers. I love the color gamut compared too traditional "wet" photographs but I always see some very light banding. Both on my ip5200 and ip8500....

 

[ghwellsjr]

I've never had individual nozzles burn out or otherwise become uncloggable but I have had electrical problems where either the whole head failed or half the nozzles failed in some pattern, always when I had the printhead out of the printer and using some liquid to clean the head. That's why I encourage people to let the printer clean its own head.

 

[nertog]

Hi again!

I cleaned the timing strip (although it was clean) and did a complete head cleaning. I took the head out and put in a small plastic container with a solution of 40% ethanol, 10% ammonia (strength 10%) and 50% dem. water. After an initial soak of 4 hours in the container with a small amount of the solution (2-3mm high in the container) I made cleaning carts with the same solution, put the printhead back in the printer together with the cleaning carts and did a deep head cleaning. After that I let them sit for 12 hours. After 12 hours I changed the cleaning solution for pure dem. water and did 2 other deep cleans. I than put the original ink carts back, waited a few hours, did a last deep clean and.......

....more clogged nozzles on the extended nozzle check. Now I got around 20 nozzles clogged instead of 1, randomly spread over all colors :/ Another deep clean didn't help to unclog them.

How can I have more clogged nozzles after this carefull cleaning procedure? Did I ruin the head somehow??

 

[Smile]

You could try this method http://www.nifty-stuff.com/forum/viewtopic.php?pid=25335#p25335
Your stream pot will be stained so you need to clean it afterwards.