Mimaki JV3-Ink Starvation??

[serverjohn]

Hey guys,
I have a JV3 that doesn't like to print black. Here is a sample image that shows what is happening. I am just printing this image with the black cartridges. I have been having this problem for a while but have been able to side step it. But now I have some time to put some more thought into it.

Is this ink starvation?

and if so, What is the next step?

I have also replaced dampers a couple times and the problem persists. Oh I have also attached what it should look like.

Thank you,
John

 

[artbot]

that looks like a data issue. ink starvation would print fine then fade a bit then drop out. maybe you should also upload a pic of what this file was supposed to look like. ...was it a black square? although there are lots of diagnostics that can isolate and possibly cure this issue. 90% of the time, a new head is the only fix.

 

[serverjohn]

I was hoping not to hear that. Attached to the original is what it is supposed to look like.
Thanks,
John

 

[artbot]

well, it looks like you aren't getting your variable data dot size to print from that head. for test purposes only, do a gradient (grayscale image) rectangle about 2x30. set your rip to print from the black only (rasterlink would be color edit/color matching/gray balance. this will isolate your black head. other rips are different of course).

see if the head prints different between non-variable data rips and variable data rips.

also print something sharp and look for overspray.

 

[serverjohn]

well, it looks like you aren't getting your variable data dot size to print from that head. for test purposes only, do a gradient (grayscale image) rectangle about 2x30. set your rip to print from the black only (rasterlink would be color edit/color matching/gray balance. this will isolate your black head. other rips are different of course).

see if the head prints different between non-variable data rips and variable data rips.

also print something sharp and look for overspray.

Here are the prints. I am not sure what non-variable/variable rips are. Do you mean that I should print them without profiles affecting them? The print I did was with no profiles enabled.

Thank you for your help so far!

There was a little overspray. On past print rich in black there has been more.

Sometimes it seems when printing a solid black bar the first 2/3 row come out perfect...

 

[artbot]

variable dot is when the head creates different sized dots to dither lighter smaller shades. in rasterlink a rip resolution will be shown at say... 720x720VD or 720x720ND.

it does look like you aren't getting the super small very fine dot patterns. but then it also isn't freaking out at small dot patterns with over spray which is common when a head loses it's very fine dot capability. there is a chance that all these tests were run in ND (non-variable) mode.

are all your other colors equally grainy? also, does the issue get better when running uni. lastly (usually first), do a damper swap. put the magenta damper/line on the black head manifold. do the same test running magenta to that head. you need to completely rule out some options. if the issue goes away, then you possibly have a bad batch of black ink or some kind of starvation. if the magenta prints grainy with some banding then you probably have a data issue at the head. this doesn't look like a vacuum problem. ...i'm assuming your test print is perfect?

 

[serverjohn]

variable dot is when the head creates different sized dots to dither lighter smaller shades. in rasterlink a rip resolution will be shown at say... 720x720VD or 720x720ND.

I am using postershop ver 6. The only print options I have are 720-VarDot 360x540-VarDot and 360x1080VarDot. (attached screen shot)

are all your other colors equally grainy?

No just the Black

does the issue get better when running uni.

We have it always running uni directional.

lastly (usually first), do a damper swap. put the magenta damper/line on the black head manifold. do the same test running magenta to that head.

I wasn't able to do this. The ink lines wont reach the black inputs.

i'm assuming your test print is perfect?

You Assume correctly.

Whew!

 

[artbot]

forgot to ask.. kind of important. is it a jv3 s or jv3 sp? i'm figuring it's an sp because sure the magenta damper on an s would reach. looks like you are in variable data mode with these prints and if so the prints look like they are missing the variable data.

at this point you are still stuck though because that kind of print can be caused by coagulated ink. it's most likely bad head, then bad data (ribbon, or slider board), then bad ink. you really have to eliminate some of these before buying a head. the data/slider board with a data swap is an easy test. but has to be done perfectly right. so... easy to do, so easy that one might not triple check. if you can't do a damper swap, do you have a brand new black cart? and did this issue appear with a new cart or has it remained between carts?

as far a test print, what i meant was the "test draw".

 

[serverjohn]

forgot to ask.. kind of important. is it a jv3 s or jv3 sp? i'm figuring it's an sp because sure the magenta damper on an s would reach.

JV3-160SP

at this point you are still stuck though because that kind of print can be caused by coagulated ink. it's most likely bad head, then bad data (ribbon, or slider board), then bad ink. you really have to eliminate some of these before buying a head. the data/slider board with a data swap is an easy test. but has to be done perfectly right. so... easy to do, so easy that one might not triple check. if you can't do a damper swap, do you have a brand new black cart? and did this issue appear with a new cart or has it remained between carts?

How I came upon this problem is a about a year ago I was trying to just print black with just the black cartridge. I had noticed a little print quality loss in the blacks with black regeneration but nothing to cause to much concern. What I found is that my rip was printing CMY in place of black(i know that sounds stupid black regeneration right!) but not using any of the black cartridge or very little.
So in other words it isn't a new problem. In that time i have replaced the black cartridges at least a couple times. Less than the other colors for sure.

And to answer your question more directly I do have 2 new black cartridges.

How do you do this data swap? And can i screw anything up?

 

[artbot]

maybe i'm not reading this right. but there is a chance that your rip is set to print black only for black files. ??? i know very little about the rip side of printing. my work doesn't require much talent. but it sounds like you set a portion of your rip to not print composite black. therefore now it can not create any grays using other process color combinations.

 

[serverjohn]

Just ignore the reference to the rip... I am sure that isn't it. I have actually had to turn off all the profiles to get it to just print black. I have been trying to print on 3m silver. If you use black regeneration it makes everything very green, but that is besides the point. I am curious what you do artbot that you know so much about JV3s. Must be a very busy shop.

 

[artbot]

i do a lot of etched metal (have the printer set up to print a proprietary acid resistant ink). like to use the printer more like a digital screen printer. i hope to abandon cmyk all together with this new custom flatbed i'm building.

here's some pics...

http://www.flickr.com/photos/alldredge/sets/72157627000489887/show/

http://www.flickr.com/photos/alldredge/sets/

i think you need to do a data swap to rule out if it is a printer issue, other than that, without running a different damper/line to it you'll just have to hope it's not the ink and blame the head. that is ruling out the K priority rip issue.

attached two renderings of how to do a data swap.

turn off the power on front, switch off the back, unplug, press the front power button four times. after this your printer is dead. if you want to get really paranoid, work barefoot.

you want to see if th graininess moves to the magenta head. keep in mind that the y position of the colors will be offset because you've deceived the printer's data route. triple check that the ribbons are moved in pairs to other heads ports keeping top on top and bottom on bottom. do not cross ribbons at the one head.

 

[serverjohn]

I made the switch from magenta to black and black to magenta... The magenta acting as black printed perfectly! So that means that it isn't the slider board and it isn't the data ribbon, right? So we are to the ink and the head right? would you suggest to flush the lines then use new cartridges or???

 

[serverjohn]

oh and i wanted to say your acid stuff is very cool! nice portfolio!

 

[artbot]

you are definitely running out of possibilities. that depends on how the data swap was configured. ....if you pull data from the head sockets or the slider board. make sure you do a test in which you allow the black heads data ribbons to be in the mix. data swaps do a great job of pointing to data issues but can leave the ribbons out a bit. print a magenta file to the black head too.

 

[serverjohn]

Doh! I had just swapped them back! K, I printed a magenta file through the black head. It turned out grainy as well. but not as bad as before???

 

[artbot]

so the black head printed a magenta file (using black ink) and the issue seemed to improve? or half improve? it's crucial that you get to the bottom of it the issue is disappearing with magenta data is sent to the black head or if the results are the same.

 

[serverjohn]

Hey sorry for the slow response. When I printed a file containing only magenta and through the black head(#2) it did print better but not perfect...

To make it more complicated, in general I do get varying results when printing just the black cartridge. Very rarely I will get something actually quite good. I am unable to reproduce that effect though.

So to clarify when I printed a file containing only magenta and through the black head(#2) it was better but did fall into the bad category.

Now I just printed the same thing again(#3) and it came out just as bad as bad as the first test print.


Now to when I print a file containing only black and through the magenta head the print comes out good. That would rule out the ink being bad correct?

Thank you for your help!!!
John

 

[artbot]

only if you have black dampers/ink lines attached to the magenta head. are you sure they don't reach? the black should have slack in the ink line being moved over to magenta. it's the longest line at the carriage.

 

[serverjohn]

I have to take back the magenta printing good. It does print better than the black but not a good as it does without the normally(with out data cables being swapped). I will try to print some pictures when i get a chance