CJV30 Disappearing Yellow Ink

[Rojo]

Got a problem with yellow I hope someone has an idea why. I've never had any issues like this before. The machine has one nearly empty yellow cartridge and one yellow almost full.

I print a 2' x 3' sign. Black and green. Looks great. Run a second identical print and about 4 inches from the end the yellow stops and the green turns to cyan. I run a test print, no yellow in either grid. I do a normal cleaning, then test print shows perfect yellow on both grids.

Run the print again. Prints fine till about 6 inches from the end and the same disappearing yellow. Test print, no yellow. Do the swab cleaning, normal clean and swap the 2 yellow cartridges with each other. Test print perfect.

Run the print again. Starts perfect. About half way through green fades a bit. About 6 inches from the end yellow disappears.

The machine does not seem to know that this is happening. No warnings or error codes. Just doesn't seem like there is enough yellow to make it to the end of the print. But it is there to start the next one.

Any ideas?

 

[ChicagoGraphics]

Possible dampers

 

[Vital Designs]

I am chasing the same issue on a JV33 . Its an ink starvation problem. I have a handful of parts coming tomorrow. I have already swapped dampers with no change but the dampers are not filling up much. I will be changing top 2 o rings on the yellows, top connectors and see if I can figure it out. I'll keep you posted.

 

[Rojo]

Looking forward to your update.

 

[Masseria]

Pressure Diference between dampers and printhead and the cartridge..

Try with a full cartridge and look at dampers when filling up ink... if you have Air infiltration....

 

[Rojo]

I am chasing the same issue on a JV33 . Its an ink starvation problem. I have a handful of parts coming tomorrow. I have already swapped dampers with no change but the dampers are not filling up much. I will be changing top 2 o rings on the yellows, top connectors and see if I can figure it out. I'll keep you posted.

Have any luck resolving this issue?

 

[4R Graphics]

Most likely dampners I know you said you changed them but I just had the same problem with my black channels on a JV33 and I had to change the dampners 2 times so 6 dampners total before problem was fixed.

If you are not using OEM dampners then you may have gotten some that are not seating or sealing right That was my problem.

Back to OEM parts I go.

It could also be the pressure difference but my money is on bad dampners.

 

[Tekkie1]

Hello Replace the 2 valves in the cartridge holder. Even though they are open they may not be opening enough.
To prove this jam something behind the valves (both yellows) to open them up fully (behind the solenoid lever).
I have had this before and its a bugger to diagnose/find.
Tekkie1

 

[Vital Designs]

Update to my issue which is the same thing.

I replaced top connectors, o ring, and dampers on both yellow lines. I ran a couple of cleanings and no ink pulled into the dampers.

I switched open the valves and pulled ink through the head with a syringe. It did a couple of test draws fine and then disappeared again.

I have just ordered a pump although I am not sure that's the issue because it would affect all colors.

I don't think it is a valve because I have tried each side individually.

I have a new head, replaced captop and all the plumbing on top of the head. What else is there?
Stumped!

 

[Tekkie1]

How did u switch open the valves? did you use the setting in the service menu or did you do what I suggested by jamming the valves open with something?
I still believe the valves are NOT opening enough and will restrict the flow of ink.
I have had this now on many occasions especially on a JV5
Tekkie1