Mimaki Jv33-160 yellow print problem

[Briansos]

Greetings,

I have been fighting with the yellow on one of my machines for a while now and Ive been able to somehow keep evreything going. I think Ive reached the end of doing so today. Here is what I am getting:

You will notice the spot that yellow is supposed to be printing is filled by another color. Usually this clears up, but not today. My new efforts have actually just ended up getting nothing to fire.

Here is what Ive done:

-Changed my dampers
-checked my pump; doesnt seem to be any problems
-checked for clogging.
-ran fill ink
-ran soft, medium and hard cleans
-ran nozzle wash

My suspicion arises from the process of trying to unclog the lines. Ive followed directions from a very useful thread here that goes through this process: #TEST->INK CARTRIDGE->CART.VALVE->proceed to open each of the valves. When a valve opens, you can hear a 'click' as it does so, I dont hear a click on one of my yellow valves. Could this be the problem? Is it something I can fix or order a part for?

Any suggestions or insights are greatly apprecaited. I'm not a mimaki tech but I like to know what to talk about/request when I speak to one so they dont just trying to send me worthless hardware that doesnt fix anything.

Thanks for your time.
-

 

[fmg]

Try replacing the capping top.

 

[Briansos]

do you mean the entire capping station? or just a portion of it?

 

[Robert M]

Cap top

You can test the cap top first if you like. There are two small black tubes that come off the bottom of the cap. Pull them off where they connect to the pump. Plug one and put a syringe on the other (either one) and pull to see if ink draws down. Any air in the draw will tell you the seal with the head is bad. If you do change the cap make sure you save the plug that is in the third hole on the bottom of the old cap and move it to the new cap.
Caps are around 89.00 from Mimaki. I have them in stock if you need one.

 

[daveb]

My experience is with a JV3, but "head anatomy" is pretty much the same... if you've a different color coming through it means there's a breech in the partition between the chambers in the head. In this case between the yellow and black. Unless I'm just blowin' smoke out my arse (which I may be) you're lookin' at a new head. I'll leave it to the experts on here.... I hope I'm wrong, those puppies aren't cheap.

 

[fmg]

Try the caping top first off and if that doesn't cure explore other avenues.
Have you called Mimaki tech line just out of curiosity.

 

[Robert72]

Usually when you see black in other color nozzles it's due to a difference in pressures between both colors. I'm not sure, but a broken valve, as you note, could make sense.

 

[Briansos]

Thanks everyone for the insight, Ive placed an order for a new cap head (thanks for the offer Robert, but the boss wants to keep with our supplier) I'll see if that does the trick. I rarely have to do any real maintance outside of daily stuff with these so I'm not too keen on knowing what certain failure signs mean. I'll update if the cap station doesnt fix it

 

[Briansos]

New cap solved all the problems, what a relief! Thanks everyone.