Question for Oce Arizona gurus

[tollerdad]

I have a 460 GT with a yellow dropout issue. It has month old ink and miniscus filters and will print ok for a while then a large swath maybe 1/4" will drop out just on one side of the yellow. A few long purges and it will completely come back with all nozzles then maybe next day be back with a bunch of missing nozzles.

So I am thinking air somewhere is getting in? Have found no leaks so thinking maybe a bad pump is introducing bubbles into ink which is causing a larger bubble in the head?

Anyone have thoughts on this?

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[SignMeUpGraphics]

It does sound a bit like air in the lines. Have you done a filter bleed under the panel around the corner from the ink bags?

 

[tollerdad]

It does sound a bit like air in the lines. Have you done a filter bleed under the panel around the corner from the ink bags?

Yes no air bubbles ink is right at top after opening valve. Do the degas filters go bad?

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[Pauly]

if you close the yellow tap, how long does it hold vacuum for?

 

[tollerdad]

if you close the yellow tap, how long does it hold vacuum for?

I will check. I assume the one on top of the carriage is what you are referring to.

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[tollerdad]

At 4 minutes you could see some ink forming on the head and around six and a half minutes the first drip.



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[tollerdad]

At 4 minutes you could see some ink forming on the head and around six and a half minutes the first drip.



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Tested again using yellow and magenta. Magenta's first drop was it 9 minutes and yellow was at 9 and 1/2 minutes so they seem pretty consistent. Having no issues with magenta head.

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[Pauly]

Ok so it's not a vacuum leak at the head.
Your head could be damaged internally or just simply bubbles in your line.
go to your "tools and utilities" and choose your channel and do a "short flush"

 

[tollerdad]

Ok so it's not a vacuum leak at the head.
Your head could be damaged internally or just simply bubbles in your line.
go to your "tools and utilities" and choose your channel and do a "short flush"

Running jobs today and the nozzles out on yellow keep moving around. Only 2 things left are degas module and printhead. Can degas cause air into head. Also is there a safe way to syringe flush the head?

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[Pauly]

Running jobs today and the nozzles out on yellow keep moving around. Only 2 things left are degas module and printhead. Can degas cause air into head. Also is there a safe way to syringe flush the head?

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Now i cannot remember exactly what it was, but my Oce tech deleted a system in the gantry. I have a feeling it was the degas, but i dont think it was.
Try changing the filters, i never have. Im leaning towards that your head could be dead.

 

[inkjet.parts]

hi...
you can remove or bypass the degassing system...
degassing means only to remove the molecular dissolved gas from the ink... this is more important on waterbased inks rather then UV or solvent...
so impact on printing is not huge ...
without degassing... if you loose 1-2nozzle here or there thats possible related to it... but from your description it´s sth else...

you should print and once you see yellow dropping out - stop the carriage and look if
- there is inkdrops on the nozzles = air leakage somewhere / dirst somewhere that catches the mist until a drop forms
- nozzles not show drop of ink = inksupply issue or head issue most probably

it can happen after sometime ... that there are inkremnants inside the printhead that tend to swim around the channels inside... and can cause those
blockings or dropouts...
electrical issue is more seldom as it should be constant problem

you can bypass the degassing filters by just closing all the ports the vaccum connects to
the small pall or whatman filter before is only there to protect the vaccum system form ink entering into it when there is rupture in the degasser or else
but ... if those filters got too much humidity form the neg pressure. they clogg as this is their function...
purge is still possible.. but they cannot properly hold the small neg. preassure needed for printing.. then your head starts to drop out also

good luck on checking all
yours jan

 

[tollerdad]

Thanks I may try the degas delete just confirm that it is or not the culprit. Double checked the ink lines and one of them attaching to head may have been a little loose. Hoping that was the problem but who knows. Thanks for all the help and feedback. Still looking for potential info on using ISO to flush the head.

 

[tollerdad]

Not sure if this points to anything specific but also get a "Ink vacuum system problem" error when I purge yellow. Just a regular purge not a long one.

 

[Ludovico]

Did you solved your problem ?

 

[tollerdad]

End result was replacing the yellow head. All problems resolved.