SJ 1000 : Why is this happening?

[Dionisio]

Hello all! My printer doesn't print solid blue (100% Cyan-100% Magenta) and also various dark shades of blue.
It runs as a 4 color printer (CCMMYK).
It's been quite some time (two months) of trying but I can't figure out what's causing the problem.
Facts:
- Print test is always perfect.
- 4 Print heads are new:
Group A(Cyan-Magenta) and
Group B (Yellow-Black).
Group C old but all nozzles firing on Cyan, magenta 94% firing - no problem visible on printing
- New oem dampers
- Caps new
- Problem remains the same no matter if 4 or 8 passes, no matter of ink amount or overprint
on any settings on any media type.
I use eco solvent inks from Sun Chemicals
I live in Greece but far away from Athens (capital). The technician after two visits fixed other problems I had
(new bearings, print heads etc) but only when he left I realized I had an issue with printing blue.
He cannot help by phone and also cannot think of what can be the cause
I did a swap between the ink tubes from cyan print head of group C to cyan print head of group A
to check if there was any ink flowing problem in the cyan tubes of group A but the problem is still there.

It seems like there is ink misfeeding but there is no ink flowing problem visible.
Has anyone experienced something similar in the past or anybody has a clue of what the problem could be?
I've been working with large format printers for the last 15 years and although I've experienced many problems
there always seems to be a new problem that I never know about!!!


Thank you in advance for any suggestions or opinions.


Dionisios


PS. I know my English sucks but remember it's not my mother language!

 

[El Barto]

How does your fill test look? That should tell you if it's incapable of printing cyan or just won't print it when you send a job.

 

[Dionisio]

Thank you for your reply.
To be honest, I never tried that fill test but instead I print blocks (e.g. 20X20cm) of CMYK+basic colors red-green-blue.
Cyan is definately the problem as all blocks of color that use cyan they come out whith stripes.
I'm new to Colorip ( So far I used to work with printshop 4 & 5 on my other printers) and I'm still learning the SJ 1000 menu but I don't think
I'm doing something wrong with settings. I'm convinced that despite the fact that the printhead is new, there must be something wrong with it!
Is it possible that maybe a damaged cable strip can cause something like that? I'm thinking of doing a swap of the cable strips before I swap
cyan and magenta printheads.
It's a second hand printer (it was bought as new in 2007 from the previous owner) so I don't know if he had that problem before and of course
he's not going to admit he had any problem for sure.
I had same problem with another printer of mine, using Seiko SPT-510, again with cyan, and that time all nozzles were firing but in print
I used to get stripes on blues, purples, dark greens and so on. The problem was solved when I replace the printhead.
But that was at least a 3 year old Seiko SPT-510. This one is just a two months old DX4!
Another thing might be the room temperature (around 20 degrees of Celcius). But I print on a Seiko 64s and on a Starjet (Chinese made using DX7 printheads)
with out any problems!
I'm so disappointed. SJ-1000 supposed to be my main printer and that problem holds back my business...

 

[El Barto]

I'd run the fill test for three reasons: A, it'll help tell you if the problem is hardware, software or firmware related. B, it'll tell you if the head's not firing at all, firing wimpy, or firing strong and fading out (which I've certainly seen happen for different reasons). C, most importantly, it doesn't cost you anything but 3 minutes. What's making question this is that you say "the print test is always perfect."

Yeah, the cables could certainly cause your problem, and of course a head could be bad from the get-go. I'm not guessing its cables right now as you'd probably be seeing weird stuff happening, instead of no stuff happening. As for heads, I'd want to work my way down the chain before going and moving heads around.