JV3 - Cyan complete band missing in the middle, cant get back to full test draw?

[backenwright]

Hi Guys

I have been running this JV3 for some years now and tackled many issues with dampers/pumps and everything surrounding them but this one has me stumped.

If you look at the attached image of my test draw I have just successfully pulled the Magenta and Black back from being completely dried out as I had an air leak in the dampers and didnt realise until it was too late so hav spent a day to get them back (this isnt our main machine anymore but is used on occassion as backup)

But the problem is that the cyan although fine before I changed the dampers on the Black and Magenta now has this nasty bit missing in the middle and after many dishway/wash/soaks you name it I cant seem to get the middle strip back up and running, it looks pretty much like a head crash which is impossible due to it not having actually printed or been used in between discovering the ink starvation problem on the other colours, and also bearing in mind at this point the cyan was printing just fine.

In every head crash I have seen so far you can tell its that due to the bend in the lines which this shows no sign of either so im a bit lost as to what to try next other than swapping out the white head (which isnt used and will take a good while to clean up) or swap for the light cyan and magenta as I really dont want to be looking at spending 1k to sort out a printer that isnt even our main machine if I can help it!

Any ideas appreciated

Leon

 

[MikeD]

have you tried soaking it for a while?
just re-read, and see that you did. maybe soak a little longer? Perhaps looking a little closer at the head itself and see if you can remove any buildup with some wash fluid and a foam swab? I haven't worked with a JV3 since the 33 came out- I know you're not supposed to touch the membrane, but I just cleaned up a JV33 that was totally covered in about two millimeters of ink, dissolved vinyl and thick adhesive by literally scrubbing the head. The operator sent a job out to a short roll of vinyl that did not detach from the core- the head just kept passing over the same area of vinyl over and over until everything melted and got stuck to the head. I thought it was trashed anyway, so why not scrub it with wash and a foam swab? I did, and now it's good as new.
Good luck, and don't trash your head just because I said!!

 

[backenwright]

Yes I have done a dishway already then turned off the machine overnight to let it sit in the cleaning fluid.

Hmm ok will give it a few more go's, I have however flushed cleaning fluid directly through the head too which didnt resolve it (that was the method I used to get the magenta and black back up and running)

 

[Solventinkjet]

Check the bottom of the head to see if there are scratch marks in the middle. JV3s have an issue when the capping station gets older and the plastic begins to warp. When the plastic warps the screws holding the capping station together are exposed more and pushed up allowing them to scrape the head once in a while. Your test print looks like that could be the case. And no, it doesn't happen to all the heads at once like you would think. I have seen 2 out of 4 heads be affected 1 out of 4, 4 out of 4 etc.

 

[MR. Graphics]

have you replaced the ribbon cable? looks like its not firing in that sector

 

[artbot]

a missing middle can be caused by a few things. a clogged manifold filter will make a missing halo in the middle of the draw. it's usually a bit feathered on the outside edge. vapor lock can create a missing spot. in order to get vapor lock out of the head, you need to pull a vacuum at the bottom of the cyan waste line. the OEM pumps just don't pull hard enough to get rid of vapor lock. when pulling at the waste line have a partner push up firmly on the bottom of the capping station to get a super solid seal. there's a small chance that there is a fracture in the cap at that point but when getting air leak there, you'll more often get intermittent lines coming and going. or that springs to that cap are weak from wear. if so, just remove and stretch out the spring a bit.

 

[mrushn]

What is the easiest way to reassemble the capping station? Should I completely remove from machine?

 

[premiercolour]

Two local customers had this problem. Problem solved. Here is what they did.

Customer 1. Changed pumps and capping station. Problem solved.

Customer 2. He bought O Rings, manifold, dampers. Problem solved.

We have these parts in stock to ship from CA.

damper
http://www.premiercolour.com/damper-regular/

manifold
http://www.premiercolour.com/solvent-head-manifold-for-epson-dx4-printhead/

Pump
http://www.premiercolour.com/pump/

O ring
http://www.premiercolour.com/high-quality-o-rings-for-oversized-high-profile-dampers/

 

[premiercolour]

a missing middle can be caused by a few things. a clogged manifold filter will make a missing halo in the middle of the draw. it's usually a bit feathered on the outside edge. vapor lock can create a missing spot. in order to get vapor lock out of the head, you need to pull a vacuum at the bottom of the cyan waste line. the OEM pumps just don't pull hard enough to get rid of vapor lock. when pulling at the waste line have a partner push up firmly on the bottom of the capping station to get a super solid seal. there's a small chance that there is a fracture in the cap at that point but when getting air leak there, you'll more often get intermittent lines coming and going. or that springs to that cap are weak from wear. if so, just remove and stretch out the spring a bit.

 

[artbot]

when working with the springs on a capping station, it's best to just take off the top portion. slide the carriage to the left. then pry one of the cammed hinges away from the bottom portion. it will become loose on one side. now go to the other hinge and pry it off. prying these off is done by pulling them toward you with slight upward pull. this will leave your capping station alignment in place. there are screws in the top of the capping station that you've removed from the base. when you remove these you'll have a mess of springs wanting to pop out. keep an eye on the springs. it's difficult to get them all back in place and lined up when replacing the top part of the caps but not impossible.

 

[mrushn]

Thanks Artbot, you should be on Mimaki's payroll with your vast knowledge. I am having problems with missing chunks on test draw that move from color to color on test draw. Do you think I didn't get the springs back in correctly? Only print problem is yellow overspray around prints. Test draws were 100% before I messed with capping station.

 

[artbot]

most likely the caps are sitting at angles because the springs aren't pushing up vertically. missing lines in the test draw that move around and come and go is often bad vacuum contact. also if you had the carriage off to the side
unsealed by the caps for a long time they've probably dried a few nozzles up. you can observe the behavior of the capping station by pressing down on the caps and looking for ones that are springing back well. this is a sign
of sticking springs. i can't see how the yellow overspray would be due to capping station alignment. that's usually a head that's too high, ink that's gone bad, or a head that is losing it's ability to fire in variable dot mode.

at the least you'll have to take the capping station apart and get those springs set right. there's a good chance that some of them aren't even pushing up much at all right now.