Possible air or ink delivery issue on Epson 9900

[kantube]

Hi, i have yet another Epson 9900 printing issue. 

When i do a test pattern print i may have a few missing nozzles in LLK.  i then trying printing a couple (5) one inch light black and the missing nozzles sometimes move to another section within LLK or more will be missing right to the ones already missing.  the missing nozzles are usually on one line and contiguous.  i will do another print of the the one inch lines until either the missing nozzles are no longer missing or stop moving.  if they stop moving i will do a color pair clean and every thing looks great. 

i then do a couple of 10x10 test prints and everything is just great.  i do a test pattern print and nothing is missing - perfect.

then i will do a 35x25 or so and will get a missing nozzle in yellow (yep the shared channel to the LLK).  i will then print a few one inch lines of various shades of yellow and as before the missing nozzles will either move to another section within the yellow or no long be missing or will get more missing on the same row. 

last night i had a few missing LLK nozzles and was ready to chuck the printer out my window but instead i wimped out and just turned it off.  this morning i turned it on and did a test pattern and guess what, it was perfect.

so to me this looks like either air or some other issue in the ink delivery to this channel.  any suggestions?  anyone else have anything like this?   

thanks
Michael

[jferrari]

When was the last time you:

1. Physically cleaned the head (cloth, paper towel, etc.)
2. Cleaned or replaced the wiper blade
3. Gave your ink cartridges a good shaking?

[kantube]

1. Physically cleaned the head (cloth, paper towel, etc.)

Never did this.  have to admit that i am very hesitant to touch the print head with anything.

2. Cleaned or replaced the wiper blade

have one on order and when i get i will replace the existing one.  looked at the one currently in the printer and it is clean with no ink on it.

3. Gave your ink cartridges a good shaking?
Have not done this either.  will give them a shake tonight.  i understand that the ink may ball up and this can cause a ink delivery issue, worth a try. 

an added note:  the print head, pump cap assembly and dampers where replaced last May by D1. 

thanks

[Farmer]

Shake ink cartridges gently when you do it.  It's more an "agitation" than a shake.

[BrianWJH]

an added note:  the print head, pump cap assembly and dampers where replaced last May by D1. 

How long has this been happening for?

Do you have any warranty remaining either with Epson or with the repair done by D1 last May?

If you have warranty with either then call them, it could be a faulty damper or printhead or as others have suggested just requires a good clean and or wiper replacement, if not and you've got warranty then use it.

Brian.

[Wayne Fox]

When was the last time you:

1. Physically cleaned the head (cloth, paper towel, etc.)
2. Cleaned or replaced the wiper blade
3. Gave your ink cartridges a good shaking?

paper towel not a particularly good idea.  Perhaps a microfiber cloth.  Also never windex (i know you didn't say that, just thought it worth repeating because it can easily kill one of these new heads), perhaps distilled water. but cleaning a head can definitely kill it.

I wouldn't describe it as a "good shaking". shaking hard can damage the port and cause other issues.  Best is to remove them, turn them over, and agitate them gently back and forth for several minutes.

Howver I've never seen a printer have issues as described from ink settling out ... to be honest I'm not sure I've ever seen any issue on an Epson printer due to this.  Theoretical problems maybe, but nothing really substantiated.

The symptoms sound like it may be a damper issue.  Also if the printer is new, I have seen some of them struggle like this for a while until you really do some serious printing and get the air bubbles out.  (one of the functions of the damper I believe, but don't quote me on that.  I'm not a service tech, that's for sure).

[kantube]

it has been a very frustrating evening...

turned on printer and did a nozzle check - it was perfect

printed a 10x7 on premium luster 260 - printed perfectly
did a nozzle check - it was perfect

printed a 24x17 on premium luster 260 - same image as above and printed perfectly
did a nozzle check - it was perfect

printed a 35x25 on Enhanced Canvas  - same image as above but this time had some banding in the background which is a gradient color.  the banding happened in one small section of the print, not the entire background 
did a nozzle check - missing two nozzles in green. the nozzles were next to each other. all other colors were fine

printed a 10x5 of various shades of green
did a nozzle check - it was perfect.  note i did not do a clean.  after talking with epson the other day, they said cleaning, or over cleaning, can cause air to be sucked back into the print head, so i really try not to clean if i small print will clear the nozzles and for the most part it works for me.

printed a 24x17 on premium luster 260 - same image as above and it printed perfectly
did a nozzle check - it was perfect

printed a 44x36 on Enhanced Canvas  - different image than above  had some banding in the background which is a different gradient color.  and again the banding was only in a small section of the print say 6" wide by 8" high.  this banding is where the gradient is darker, similar to the banding that happened before.
did a nozzle check - it was perfect. i did a second nozzle check to make sure too.  yep i do use a magnifying lens to check.

chucked the printer out my second story window! well no but i really want to. 

so it looks like i did have air or something causing the missing nozzles.  but now it seems like i have an ink delivery issue, may be the same issue causing the missing nozzles but who knows.  this banding seems to happen in darker sections but only on the canvas prints, not on the luster paper.  could be that it shows up more on canvas or that the prints are bigger on canvas and the printer cannot keep up with the ink demand, just really guessing now.

no i do not have a warranty on this printer.  however, i will be calling Epson tomorrow but don't expect anything more than them telling me to call D1.

I am thinking the following are the standard items that get replaced with this type of issue
Damper/Selector unit unit $174 + $13 for two rubber seals
pump & cap assembly and wiper $245

if anyone has any other suggestions... 

thanks
Michael

[BrianWJH]

this banding seems to happen in darker sections but only on the canvas prints, not on the luster paper.

if anyone has any other suggestions... 

Michael, not familiar with your 'enhanced canvas' however going from Lustre to Canvas might have invoked a PK to MK ink switch not sure.

I guess the canvas would require a heavier ink load than the lustre.

Could be a pressurization/pump or ink cart leak problem.

Brian.

[kantube]

there is no black ink switching when i print on canvas. i use enhanced glossy canvas which has a photo black icc file from epson. 

but your comment about a leaky cart got me review the images and where the banding happens.  on the first image i printed the banding is located within a 3 inch high section near the start of the print.  this banding is vertical but happens from edge-to-edge of the print.  the gradient colors are very constant from edge-to-edge.  however there is no banding future down the print, but he color of the gradient is different, deeper back and then to blue and then light blue, which printed beautifully (really shows why you put up with epson).  the color where the banding happens is a combination, to my eye, yellow, green and black. 

the second print has a very large gradient from the top to the bottom of the print and from edge-to-edge.  the color is predominantly green/black gradient.  the banding happened in a small section near the end of the print (5"x3" of banding only).  again the color is green and maybe some yellow and black.  the greens are darker where this banding is happening.

when i print these images on luster at 24" wide on luster pager they print perfectly.  to be honest they colors are great on luster paper and there is no sign of banding.  the banding only happens on canvas. 

so tonight i will try narrowing the colors down to where the band happens and see if it is green.  the green cart is low, but not empty and does not have the warning.  the yellow is 99% full and new.  i do have a new green cart and will replace the old one and give that a try. 

[Wayne Fox]

Missing nozzles/banding are usually agnostic to the paper in the printer.   when you say the bands are “vertical” that also doesn’t really sound like a nozzle problem.

If the image looks great on luster, but has a problem on canvas, you may want to try and tweak the feed, width and gap settings. 

[kantube]

ok so an update:

took 100% crop (13x5) of the sections of the pictures that had vertical banding and printed them on 13inch wide canvas (did this to save canvas).  well the banding was not visible on these smaller prints. in fact the prints are great

took 100% crops (44x5) of the sections of the pictures but only 5" high.  this did show banding. 

replace the green ink cart with a new one since it was low but not below 1%. 

reprinted the 44x5 crops on canvas and the banding was visible.

printed the 44x5 crops on canvas with high-speed turned off - no banding!

did a head alignment using enhanced matte paper.

reprinted the 44x5 crops on canvas with high-speed turned on and the banding was visible.

did a nozzle check again and it was perfect and i did check with a magnifying lens. 

printed a full size image, only one because it is very slow, and it is perfect! not close but perfect!

well i am not a production shop so printing slow is not a major issue for me but damn this took a long time to figure out, not to mention the amount of ink and paper/canvas.  I don't know what the issue is with these images or printer, any ideas??  i will be calling Epson to see if they have any idea or if this is a know issue with darker gradients.

i did upload some images of the banding, not sure if you can see it very well but trust me it is very obvious.