L26500 banding issue

[bigben]

I don't know what to do.

Whenever the number of pass (6,8,12) or material (I've tried banner, poster, vinyl), I have horizontal banding in my print (about 0.25in wide). We see it more in dark colors. I've done multiple print head cleaning, printhead alignment, lubricate the carriage, update the fimware of the printer, create a new profile for my poster, even took off all the printheads to manually clean them and maybe other things I've forgot.

I'm out of idea or maybe I'm missing something?

I'm using Caldera as a rip.

someone have any suggestions?

Ben

 

[MikePro]

Pics of banding and test print, or it never happened.

 

[Bly]

How's the test print? Could be a bad head.

 

[bigben]

here are the pictures. The printer said all the printheads are good and the test print seems to be fine... On monday, the printer ask me to change a cyan printhead. I've forgot it. But when I start up the printer next day, the printer said the head was fine. And I've done maybe 5 clean today on all head, even a ''manual'' one and the printer still say all printhead are ok.

If you need anything else, let me know.

 

[MikePro]

your yellow test print doesn't look so hot. black is kinda grainy too. Your test print should look more like this:

is your maintenance kit near replacement? that could do it.
any head strikes or media jams lately? that'll definitely do it.

at the very least, printhead replacement is cheap. ...and they don't expire too quickly in storage, so you might want to order them now, just in case, while you scratch your head. Tis the season for shipping to take its damn time...

 

[MikePro]

also, glossy media can affect the automatic printhead alignment feature. you might want to try a manual printhead alignment.

 

[bigben]

Ok, I've found that a cyan printhead had some misfiring, I've changed it. Print the test and everything's looking ok. Still have the same banding. Oh, and the yellow part is good. It look like this in my service manual.

Now I'm trying the manual alignment....

 

[bigben]

even with the manual alignment, I still have the same problem.

I have no idea what to do now.

 

[Caldera_Ryan]

Just a thought, Have you checked the power input to your printer. I have run into the issue that sometimes vertical banding is caused by inconsistent or "dirty" power.

I have also ran into cases where it was caused by a faulty or dirty encoder.

 

[bigben]

Just a thought, Have you checked the power input to your printer. I have run into the issue that sometimes vertical banding is caused by inconsistent or "dirty" power.

I have also ran into cases where it was caused by a faulty or dirty encoder.

But in my test plot, I should see a problem... right? But there is nothing that I can see. Could it be Caldera?

 

[MikePro]

Unless I'm seeing it wrong, your yellow test plot should be yellow... but isn't it printing magenta?

 

[bigben]

Unless I'm seeing it wrong, your yellow test plot should be yellow... but isn't it printing magenta?

when I check my service manual, it is supposed to look like that. If I check carefully, the yellow lines in it are fine.

Now I try to figure on how to print an advanced printhead health test plot. It do not fit with what it says in the service manual.

 

[MikePro]

wierd, i got that screenshot from my digital copy of the service manual BUT it's confirmed, supposed to look that way.
pic of my test print attached, same as yours and I have no banding.

maybe a OMAS/feed comp. issue? ...otherwise I have no idea aside from simply replacing more heads.
wish i could help more, but i'm new to this machine as well.

 

[bigben]

wierd, i got that screenshot from my digital copy of the service manual BUT it's confirmed, supposed to look that way.
pic of my test print attached, same as yours and I have no banding.

maybe a OMAS/feed comp. issue? ...otherwise I have no idea aside from simply replacing more heads.
wish i could help more, but i'm new to this machine as well.

I've talked to my rep and another guy had the same issue as me. I have a fine yellow line in my banding and there is a majority of yellow when I check the first pass of printing. I already had a yellow/black printhead so I change it and it seems to improve the print a little. So I'm waiting the other printhead on Monday and we'll see.

 

[bigben]

ok, here is the follow up on my problem.

even if the test print where perfect (no alignment problem and minim defect nozzles), the prints came back to normal after changing the two cyan/light cyan and the two black/yellow printheads.

I'm writing this here in case someone hit the same problem in the future.

thank all for your help.