HP Latex 300 3xx Plot Test - Dark Banding - Help Required - Please :-)

[J4cko]

Hi Guys
Hope you can help please.
I'm reasonably familiar with the HP 3xx Series Latex

Recently on a couple of printers , when performing the plot tests, we have seen an irregular dark coloured patch in the yellow plots.

The latice / grid of yellow and all other colours is intact, with no breaks, but the solid vertical bar of yellow, has dark mustard colour patches in it.

As i have said, have noticed on 2 printers, and both times on the Yellow ink

Please see the attached plot test, with the dark mustard patch in the yellow vertical bar.

I have cleaned the heads through the print cycle
Forced solid yellow prints with ICC turned off, through the machine a couple of times, in case of a blockage.

And also manually removed, soaked and wiped the yellow / magenta print head.

Another head clean and block of solid yellow forced through, but still the mustard patch on the vertical yellow bar

Please advise ?

The head is out of warranty, but nobody i know replaces them at 1000ml

Its strange this is something that has only happened recently, as we have owned Latex machines for years.
Happened on 2 printers, and it came to light because of colour drop and banding

Bad batch of ink ?
Any suggestions ?

No problem replacing the head, but its strange we havent had this dark mustard colour appear in the banding in all the years of owning latex machines

Look forward to any words of wisdom

thanks a lot
Jack

 

[ddarlak]

Check how many jets are out and pray that that's the issue, otherwise you have ink contamination and it's gonna cost bucks.

HP 315 Magenta fading as it prints

I'm not sure what's going on. It appears to be something with magenta. I'm trying to print some 3" circles today for a job and looks like this... HP 315, Generic Self Adhesive 10pass - this what I typically use and haven't had issues like this. Any ideas? I'm stumped because everything looks...

www.signs101.com

 

[cornholio]

Looks like contamination of magenta into the yellow channel.
Since you have multiple units, you could swap maintenance cartridges to test. I have seen this after SMK3, after a buildup of ink on the maintenance cartridge.