Need Help Roland RF-640

[Witer]

Hello,
Just need your expertise...
When i print 100% of each cmyk bands i have got vertical banding on black and cyjan. Magenta and yellow is ok.
Of course every color which is dark has banding. Machine is new, month old. Service tech do not have clue and postponing visit to solve this problem.
What can cause such phenomenon...
Thanks and regards
Kris

 

[edcooleyar]

What type of ink, paper and rip are you using?

 

[Joseph44708]

Print heads are garbage.
Happened to me, I replaced in my xr640 and within two days I was getting banding.
Got another set of new heads and printing great.

 

[edcooleyar]

My understanding is vertical banding is perpendicular to the movement of the printhead. Usually not caused by faulty heads which band the same direction the printheads move.

 

[Witer]

Well,

What type of ink, paper and rip are you using?

Thanks,

I appreciate your reply...
Regarding paper, I was using Satin paper WJET SATIN 200g/m2.
RIP: VersaWorks,
Ink: Bordeaux fuze nr4p...
Doesn't matter which profile I used, which temperature, still have this banding which is perpendicular to the movement of the printhead.
Service tech was advised to change feed adjustment which limit this banding. But I received too long prints...

For me strange is that I see banding only with black and cyan. Issue is not visible with magenta and yellow.

​

 

[balstestrat]

How about you post some pictures of the issue?
And nozzle check as well?

 

[Witer]

photos

20210629_115448.jpg

drive.google.com

https://drive.google.com/file/d/1V6hPqqpJiS_1o-y3BbexzG-OTsgDlz-c/view?usp=sharing

nozzle-check.jpg

drive.google.com

 

[edcooleyar]

Try turning the vacuum as low as possible. Raise the platen gap and add a pass delay if possible. Looks more like a pump or head flow problem than vacuum or cockling.

 

[Witer]

Try turning the vacuum as low as possible. Raise the platen gap and add a pass delay if possible. Looks more like a pump or head flow problem than vacuum or cockling.

Well, today I made default calibration of feeding with my paper. The strange was that default vale was +0.3% in the service menu.
I used different media paper and foil and with 6 pass I have this vertical bands. But with 8 pass it is significantly reduced however it is still present.
In my opinion there can be ink flow issue or head is faulty, because issue is happened only with cyan and black color. Magenta and yellow is ok. The lighter and darker bands are in the same place on cyan and black.
How I can check if it can be link to head or to ink flow...
thanks a lot for your support

 

[Witer]

Additionally I wanted to point out how the feeding adjutments looks on this paper.
There is no clear enough clearance between columns. please see below photos:

feed adjustments.jpg

drive.google.com

feed adjustments-conection.jpg

drive.google.com

Additionally when I check this via magnifier there is strange situation as few begining dots are smaller comparing to the others. On the foil dots are the same...

feed adjustments - dots.jpg

drive.google.com

feed adjustments - dots_.jpg

drive.google.com

For each print I have different gap between columns... how it possible...
BR
Kris

 

[Nino Graphics]

Hi, did you fixed the problem?
I bought a new rf-640, and it has never printed without banding problems, also the prints are inconsistent somehow.
I think varranty is the only way to fix the this.


Br, Nino