Jv33 yellow very faint

[mtygabriel]

Hello there,

I was halfway through a roll, went to local mode, cut the printed portion, and hit remote again. Mimaki continued printing for another foot or so before the Yellow went out completely.

I have done multiple, many hard cleans, nozzle washes for 30 min to 60min, fill up inks, Discharge and Wash, and have not been succesful in unclogging or fixing problem. I test checked valves in technician mode or so pressing the FUNCTION and REMOTE buttons when turning on and valves check out.

I've read many threads and that suggest troubleshooting dampers, cap top, tubes from cap top to pump, etc. Does anyone have any videos or pictures that can help me visualize where and how exactly to check these things so that I don't mess something in the process. I want to be careful not to let air into the tubes, etc.. as I heard that in itself is a problem.

Help!!

Thanks

 

[SightLine]

Just to eliminate it... the current active cartridge is on level 2 or higher right? There is a chance if it is on 1 it is actually empty and the empty flag just did not pop out.

 

[mtygabriel]

Sightline, that's happened to me before and I did check that. Indeed it said "1". The thing is that I have a bulk ink system so the level reading is not necessarily the actual ink level in the tank/cartridge. I did reset it, and it goes automatically to "9". Because I had a Bulk Ink Tank, I failed to mention that I did not have the other Yellow slot cartridge plugged in so that it wouldn't switch over, but I assumed that the valve for that slot would simply remain closed.

I am trying to think of additional information I've might ommitted. I had been printing this job for three days, which consisted of about four 75ft canvas rolls. In the morning would do 5 to 10 min wash, and at end of roll another wash, and before leaving 30 to 40min nozzle wash. I use third party ink, Durafos (Korean), but that is also not a new ink for me for I have been using it for three to four years now, since I bought the printer new three years ago or so.

I've had colors stop printing in the past, but I had previously solved by realizing things like the cartridge was really empty eventhough it read "1", or the cartridge expiring, or actually some minor clogging of the lines, humidity, etc. but definitely I have not had an occassion like this where I've done so many cleans, washes, fill up inks, discharge&wash, refill, dehumidy the air, etc like this to no avail.

I'd like to think that maybe I've introduced air or negative suction in the lines since I started using these bulk ink systems as an added variable. I am ready to attack this problem but I want to first understand what I am doing so that I don't make things worse and because now I am under the gun for time.

Thanks!

 

[mtygabriel]

...one more thing. While doing the Discharge&Wash I did notice that the yellow did go through and emptied out, but with the cleaning solution coming next into the lines I was able to see that it seemed to travel down slower and be the last to empty its solution out of the lines. I would notice the others were empty and the yellow lines still had liquid. Eventually they emptied out, but it might mean something.

 

[nashvillesigns]

i am thinking air in the lines. you could open the "Gate valve" and pull out the air pockets with a syringe in the damper.. My yellow does a similar thing. except only when switching between the two cartridges. i was told the cartridge valve does not open after it switches. hence, i run out of yellow.

 

[mtygabriel]

Ok. So I need to dislodge the damper from the carriage and on the bottom side of the damper connect the syringe. After that is it that I manually open the valve for one or two of the yellow cartridge that are located behind the cartridge bay? Am I to suck ink into the syringe until it is full, or what should I expect to happen? Thanks!

 

[mtygabriel]

...what if anything does it mean that when I do a fillup ink I hear the clicking sound of the valves opening and the lines do get filled up with ink?

The air could be trapped not only in the lines but also in the damper I take it. I probably mentioned it earlier but the one of the two dampers I found had little or no ink and did fill up when I did the fillup ink procedures and when I did the Discharge and Wash.

I also just followed something I read here where I moved the Carriage to the Carriage cleaning bay on the left side of the printer and press the circular pressure chamber on the damper to squeeze ink through the heads and be able to see the ink come out underneath. I was able to see the ink through on all the colors but it took a little more pressure for me to get the yellow out but it did come out.

thanks

 

[mtygabriel]

Opened yellow valves and took out yellow dampers. I did have air in the lines. I was able to get what appears to be most of it, but here and there I am still seeing a tiny bubble move about. I did a fill up ink at the set of bubbles left in the line went into the damper, but I don't know if that air exited the system.

What I have also done is tested with a syringe the waste tubes between the capping station and the pump. I clamped one side and on the other side I used the syringe to draw waste ink. I drew air with it, which leads me to believe that I may also have a sealing issue with the cap top as indicated in other posts. I ordered one yesterday and won't get this until Tuesday in case it might be it.

 

[mtygabriel]

I got the cap top in the mail, installed it and there for the first three or four test draws did not see a change. I drew some ink from underneath through the tubes below the cap top and after a couple tests, both yellows were printing as it should whereas I had started with just the right working.

Unfortunately, after about twenty feet or so the left side started being starved again. It is not completely out, but I cannot get the yellow on the image print I need. I am at a loss.

Any ideas?

I changed the tubing below the cap top as well as the pump and its tubing.

Could it be I am looking at a clogged manifold or printhead?

Thanks for your help!

 

[mtygabriel]

More cleaning, more washing, more suctioning, more pushing and pulling ink, etc... the printer is now printing fine.

Thanks for the help!!!

 

[SightLine]

Could be the bulk system itself. I did a lenghty post on the problems with most of them a while back. If the cartridge part of the setup is sealed and does not use a bag, as ink is drawn out then it creates negative pressure in the cartridge which in turn causes ink starvation since the pumps and ink train have to overcome this. This sort of scanario ultimatley results in leaks, damper failure etc as the pumps try to overcome the negative pressure.

If however the cartrdiges use a bag internally then those can collapse as ink is used (how regular cartrdiges are designed) which eliminates the issue. The other option is ventilated cartrdiges but then you potentially have issues with too much positive pressure, ink contamination from exposure to air, etc.

I recently went to a bulk system on ours but it uses 2 liter bulk ink bags which feed catrdiges with bags in them. It's a sealed system so no air is introduced and the bags collapse keeping consistent system pressure just like a regular cartrdige does.

 

[mtygabriel]

I think you've got a very legit point there. My bulk ink system is composed of the cartridge component that feeds the ink to the tubing and above it is the "tank". You pour the refill ink to the top of the tank and it drips to the cartridge via a small tubing. I take it I have the ventilated type, as the cartridge has a small hole at the top of it. The pressure is suppossed to be regulated by an internal floater which you can adjust up or down to increase or decrease pressure.

I have also considered that maybe as the ink level drops in the cartridge, there is less pressure to push the ink. So I have the floater set to high pressure allowing more ink from the tank to pass down to the cartridge.

Nevertheless, the pattern with the yellow seems to be on the left side of the nozzle. I swapped the yellow damper positions and the lack of yellow still remained on the left side when printing.

I am almost inclined to believe I have a clogged manifold or clogged head. But what bothers me is that I will get both yellows looking fine on a test print, print a batch and then start another batch and the left side starves again.

Would you discard the manifold or head?

Thanks

 

[mtygabriel]

SightLine,

Checked out that thread on the Triangle Bulk Ink System. Looks real nice!!! Didn't know what factors to consider when I purchased mine. I'll keep it in mind for thefuture.