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over spray on test draw

Spencer McMurtry

Spencer McMurtry

New Member
Hopefully this is a easy fix as this machine has new heads / dampers / captops. i am running dual cmyk with a triangle bulk ink system... the machine was printing with no over spray just a few days ago, i have tried a head soak / cleaning i have also switched the ribbon cables on the heads and the problem stays with the head. i am getting overspray on anything on only the black head all the other heads are perfect, here is a high res scan of the test draw for black http://img32.imageshack.us/img32/1940/blacktestdraw.jpg let me know if you have any ideas.

Spencer
 
Letterbox Mike

Letterbox Mike

New Member
How long of a captive head soak did you do? You might consider doing one overnight or even over a weekend to see if that helps. If it doesn't, I'd say try pushing some cleaning fluid through the head manually with a syringe, but that's risky and should be a last resort.

It's strange that it's such a consistent overspray and not random or focused in one specific area. If it were more random it would make me think there's just debris misdirecting the ink spray, but that looks like there's more going on. How new is the head? Is it possible that the head is bad? The last head I changed out took three tries to get a good functioning head, direct from Mimaki. The first two they sent were bad right from the factory, so don't rule that out.

Short of that, I guess the next thing to question is the ink itself. Have you had success with this bulk ink before? Did the problem start after switching to the ink? If so, maybe the ink is causing the problem, but you did say it just started a couple days ago so that may rule this out as well. But if the new head was faulty, it may have taken some time for the issue to show up, or maybe the aftermarket ink has aggrivated the new/faulty head. Just speculating.

How to regular prints look?
 
Spencer McMurtry

Spencer McMurtry

New Member
i am doing a overnight head soak, i bought this machine used in "working condition" so far ive had to replace 3 heads in it. and 1 out of the 3 heads was defective, it had over spray only on variable-2 dot size then the head caused all the other heads not to fire.. replaced that defective head and the machine was working for about 3-4 days printed a wrap with it let me sit 3-4 days and booted it up to do another print and this is what im getting earlier it was printing perfect. all i have i printed on this machine since i got it was 1 wrap plus about 2 rolls of calabrations... i have replaced just about everything in this machine, captops / sliderboard / dampers / o-rings on the dampers / bulk ink. i also did a tried another motherboard when i was having the issues with the varaible-2 overspray (which turned out to be the defective head) it has the oringaly motherboard in it now. i will see how the head looks tommrow and post pictures of another test print. the overspray is on varaible1 dotsize and varaible2 i have not tried normal dot sizes..

has anyone ever had there machine lockup durring a test draw? mine has been doing that alot lately and i have to turn it off and unplug power to get it to do a test draw without locking up.

also when you do the capping calabration when you set the asurb postition the service manual says .5mm from the heads to the captops is this the first head or the last head or? becuase when the first head is at .5mm the last head is like 1mm from the captops is this normal?

Thanks for your post!
 
Letterbox Mike

Letterbox Mike

New Member
Post up a scan of the new test draw after the head soak, I'm curious to see if it has any effect at all on the problem. The more I think about it, the more I suspect it won't, actually. The uniformity of that spray has got me thinking more and more it's a defective head or a problem with the ink, or both, since every single nozzle is firing and they appear to be firing correctly with no deflection.

You said this head was replaced. How long ago? Do you have another head you can swap out for this one (I know, pita) to rule out the head?
 
Spencer McMurtry

Spencer McMurtry

New Member
the head has only been in there maybe a month i have only printed around 30foot on it and i have a few heads around that are missing a few nozels.. but after spending 100+ hours on this piece.. i really don't want to start back at replacing heads this is ridiculous, i need a machine that works.. just did a test print after a 10 hour head soak EXACTLY the same.
 
Spencer McMurtry

Spencer McMurtry

New Member
would there be something wrong with this machine causing heads to go bad? is it normally for a head to work for a month then just quit? does anyone want to buy a sp-160sp? im ready for a roland...
 
Spencer McMurtry

Spencer McMurtry

New Member
i am buying another head so far i have bought 5 heads for this machine 2 of which have turned out to be defective... i will put the new head in and keep you posted. is it possible for a bad motherboard to be causing these heads to go bad?
 
Spencer McMurtry

Spencer McMurtry

New Member
UPDATE!!! ISSUE FIXED Solution:


solution:
From K. Leung on mimakjv3 printers on yahoo:
You know.... after thinking about this for a while, I think you have a voltage
problem. If there is too high of a voltage to the head, you'll get a lot of
overspray. The voltage is regulated by a bank of transistors on the main board.
If the transistors are going, this would be a symptom.

There are lots of causes of overspray but because you mention that you changed
the head and it was ok for a while and it came back, I think the chances are
much greater to be cause by the above problem. The reason I say this is that a
new head can take a little bit of electrical "abuse" before it starts having a
problem. After a while, the head will slowly get damaged with the increased
voltage supplied by the main board - showing the overspray. Eventually, the
head will just stop working.

Switch the main board if you have a spare or can locate a loaner and I suspect
that the overspray will disappear. Your alternate thing is to check the
transistors in each of the banks to see if they are damaged.

If you do find a set of transistors that are bad and can't locate them locally,
we carry these (they are very difficult to source).

Kent
www.macmedia.com
Click to expand...

I replaced the motherboard as Kent recommend and the issue has went away, the black head might still need replaced not sure.. but the black test draw is perfect, i will rerun all the calibrations and keep you posted.
 
Spencer McMurtry

Spencer McMurtry

New Member
UPDATE MORE PROBLEMS...

the problem went away with the over spray on the black head when i replaced the motherboard but now there is a over spray on the yellow head on a test draw (the over spray isnt near as bad as what was going on with the black) which was not there before i replaced the head... WHAT IS GOING ON!!! here is a picture of the test draw http://infinitegraphics.net/jv3_problems/test-draw-new-mboard.jpg (notice its a 15mb file)

when i do a 720x720 test print CMYK there is no over spray on any colors... now when i do a 1440x1440 test print cmyk there is a TON of over spray on yellow picture http://infinitegraphics.net/jv3_problems/720vs1440-CMYK-test.jpg

i have had this happen before with a brand new head (i thought the head was defective... perhaps not?) replaced the head and the issue went away... but why is this happening? i dont understand.. i have replaced almost everything in this machine, motherboard / slider board / 4 heads, cap tops, dampers, o-rings.

The biggest thing that i don't understand is why the yellow head was fine before i switched out the motherboard and now with the new board in it is giving me problems.

i have tried a different slider board / different cables, and i double checked the head id. the dampers / ink lines are all perfect.

this is kinda like throwing money in a big bucket then just lighting it on fire, every time this machine breaks it takes a small piece of my soul. please help.
 
Spencer McMurtry

Spencer McMurtry

New Member
UPDATE here is a high res scan of the all pattern test, I know most of the calibrations are off i just replaced the motherboard and havent ran them yet. i am curious as to if everything else looks normally? there are a few spots if you look at the yellows and some of the blacks that just don't look normally to me and thought it might help solve the other problems i am currently having
image is here (note 20mb file) http://infinitegraphics.net/jv3_problems/all-pattern.jpg any input would be would be greatly appreciated!
 
S

SE SignSupply

New Member
How about a static issue? Any chance you are generating static while printing causing the problem to come and go? (as the machine charges and dis-charges)
 
Spencer McMurtry

Spencer McMurtry

New Member
SE SignSupply said:
How about a static issue? Any chance you are generating static while printing causing the problem to come and go? (as the machine charges and dis-charges)
Click to expand...
how would i check for this? or solve it? i have no idea what a static issue is? i have a sp-300v plugged in the same outlet and same pc with no issues ever.
 
particleman

particleman

New Member
I would try to swap cables and let the yellow channel drive a different head and see if the problem stays on that head or moves to the other one, or it even may go away if it is a voltage issue, if that is the case I wouldn't run it very long on a good head. That should narrow down the issue.
 
Spencer McMurtry

Spencer McMurtry

New Member
particleman said:
I would try to swap cables and let the yellow channel drive a different head and see if the problem stays on that head or moves to the other one, or it even may go away if it is a voltage issue, if that is the case I wouldn't run it very long on a good head. That should narrow down the issue.
Click to expand...

problem stays with the head when you switch the cables. bad head? that's the only thing that makes sense. it has a new mboard / new slider board / new power supply and 3 new heads. the yellow head is the one i havent replaced will you look at the "Test draw" image i posted and see if this looks normally to you? link to image. http://infinitegraphics.net/jv3_problems/test-draw-new-mboard.jpg
Thanks
 
B

benjercorp

New Member
Boy I've seen worst last time last week I was in a Caribbean Island and those printheads were all way worst than the ones you have so believe me oyu're good to go...
 
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