UJF6042 sudden loss of White White head and channel, but test prints fine

[btxmedia]

I am totally stumped. 6042 mki has been printing fine until today. Both White channels on head 4 won't print, previous job ran fine so it wasn't like a mechanical issue.

* Test print works great and both White channels test print
* White maintenance function draws a vacuum and emptied ink through cap station
* New white chips installed to test
* Rebooted printer, pc, rasterlink, etc

Printer gave "ink near end" error on the Primer channel so it won't enter cleaning mode. I put an older chip that was long expired on the primer channel, and it lets me enter cleaning mode, and I can see the White/White head 4 clean up. I tried to "fill up" the primer channel to see if I could reset the ink level, but the machine wouldn't leave that screen so I had to power down. After doing that the white dropout started.

I can't actually print with the expired Primer chip so I have to run jobs with the "ink near end" chip that won't reset the weight. This is the only thing currently amiss with the printer. I have a new one arriving this week (I don't actually print Primer/Clear that head has been clogged for years)

Nothing in rasterlink changed. Special layers are setup just like before.

It just won't actually print anything for White! Any ideas?

 

[btxmedia]

When I run a job in rasterlink I can isolate just the White/White special layer and send that as a test only. Avoiding sending any other colors. Printer receives the data fine and runs the whole job, just nothing comes out.

 

[Smoke_Jaguar]

White ink is pretty high maintenance on the 6042/3042 (MKI and MKII), even with the circulation system. The MK1 in my limited experience tends to stop printing if too much air gets into the head and you need to do the air bleed procedure with the special tool (or just heat up and bend a plastic cleaning swab handle). Should be covered in the operations manual in detail.

 

[btxmedia]

I'll deflate it tomorrow, have the tool. Reset the clock and got all the chips working so it's not that error now. Test print is still showing White/White running fine - will let you know how it goes.

 

[btxmedia]

Deflate on channels 7/8 White/White went fine. Good draw of ink, no bubbles.

 

[btxmedia]

Ok found a problem!
Test printing right from the printer still works.
But any of the service mode "Check Pattern" prints do not work on White/White.
All other colors work - but as soon as either White channel is selected to go, the head moves and UV lamp goes on - but no ink.
So it's like it won't print anything other than nozzle test.

 

[Smoke_Jaguar]

Are you using RasterLink?

I've tried Onyx and Flexi, and it's TOTAL GARBAGE with these printers, never got white to work other than on seemingly random prints.

 

[btxmedia]

RasterLink yes 5.16 which has been surprisingly bulletproof once set up.
Currently thinking I may just swap this head out. But will first remove it from the printers inkset config and just run as CMYK then reintroduce it as into the inkset.

 

[Solventinkjet]

It sounds like maybe the head is failing. Sometimes the variable dot function will malfunction and only allow a certain sized dot to to fire. So that would explain why it fires on the nozzle check but not more involved patterns that may use the variable dot function.

 

[btxmedia]

It sounds like maybe the head is failing. Sometimes the variable dot function will malfunction and only allow a certain sized dot to to fire. So that would explain why it fires on the nozzle check but not more involved patterns that may use the variable dot function.

Very interesting idea. Do you know off the top of you head if any of the service mode Check Patterns do not use the variable dot function?
My copy of the service manual says these are available, I've been doing 100% and V-LINE. Will have to try all.
100%
50%
25%
6.25%
NOZZLE
V-LINE
H-LINE
SLANT
GRADATE
V-1B1W
H-1B1W
FEED, GRID, DIS- PLACEMENT, DROP
CHECK*

 

[btxmedia]

FEEDEVAL worked in service mode and printed from both White channels ok. None of the others seems to print.

 

[netsol]

Are you using RasterLink?

I've tried Onyx and Flexi, and it's TOTAL GARBAGE with these printers, never got white to work other than on seemingly random prints.

odd. WOULDN'T YOU THINK, 100% output from the white channel would be pure white?
C0 M0 Y0 K0 W100
you obviously have the mimaki experience I DON'T HAVE

i always felt they were peculiar beasts...

 

[Smoke_Jaguar]

Best use of Onyx/Flexi is to send data to Rasterlink anyways, defeating the point. Then again, I use Vinylmaster for the cut. White/clear/primer plates are easy to make for testing as well.

 

[btxmedia]

Fixed it!

Ended up changing the inkset to be just MCYB---- in effect removing Head 3 Clear/Primer and Head 4 White/White. To remove a head like that from the inkset it needed 2 cleaning cartridges. And it burned through 2 full 220ml ones just to disable those heads!

Then, I readded The White/White ink so it's MCYB--WW. It did a fillup and worked fine.

Back to printing as expected and the Test menu prints did fine.

I left my trashed Head #3 Clear/Primer disabled so I don't need chips on those anymore at least.

So to recap:

Cause: The error was it got stuck in a loop about "ink near end" on Primer, while also having too old a chip to "fill up" the Primer channel, and there was no way to leave the menu without hitting the emergency stop button and/or powering down.

This - somehow - screwed it's settings up internally about the White/White head also.

It would not print anymore White ink special channels in RasterLink. Or from most of the #TEST print options.

I imagine this could happen to anyone else. So if you have a sudden head drop off, but a few of the Check Pattern prints work, and the main Test print works, try disabling/flushing out the head then readding.

 

[Tipgypsy]

Ive had channels drop out after quick power fluctuations, Causes strange things to happen to my 6042's usually just shut them down and restart and everything is rosy again.