CJV30 Cyan suddenly completely missing

[Neil]

Hi all,
as the title says my cyan has decided to not print at all out of both channels (2x CMYK).
The last thing I did was print a large run with some pretty heavy blue coverage. I installed a new cart half way through no problems.
It finished the run perfectly.

2 days later I go to print something and there's no cyan nozzles firing at all.

I've just done a damper swap - pulled a magenta and cyan damper and swapped them into their respective head channels.
Did a couple of cleans and a test print or two.

The cyan printed out of the magenta channel as expected - meaning it's not the ink or damper etc.

I got no magenta out of the cyan channel - meaning it's probably the head or something electrical...

So that's it for me. I'm waiting to hear back from a tech but it's out of warranty so I'm hoping he doesn't have to start swapping expensive parts till he finds the solution.

Any ideas out there?
Anything as simple as a fuse I could check??

 

[Rooster]

I'd say swap the data cables, but it's a single print head so that won't work.

You may need a tech to check that a board hasn't fried.

Have you done a nice long nozzle wash to make sure that it's not just the cyan drying out at the head?

 

[Case]

Is it pulling ink through the head during cleanings??? That will eliminate damper, pump, etc...........You will see ink in the cap of the color you are having trouble with after a cleaning..............

If you see ink in cap after cleaning then there is a great chance it is the main trailing cables from the slider board to the mainboard.... They have been known to fail............ IF that is not it, then you start looking at slider board, etc....

Some people even have had broken ink cart sensors and after one ink runs out it doesn't switch properly and gets air in the line and sometimes air lock in the head........



Case

 

[Neil]

Yep I did a nozzle wash and several cleanings and an ink fill when I first saw there was no cyan.

Case, that's a good point about ink in the cap - there's no cyan there.
Seems it's not pulling any through the head.
Maybe capping station, pump or blocked head?

I've removed the front cover so I can see the drain tubes. There's not much going through them until the last 10 seconds of the cleaning cycle after the head has finished refreshing.
That then drains away okay but there's no seal at the cap at that time.

Going to try to eliminate the stuff under the head...(cap, pump, tubes)

 

[Case]

I always like to look at cheapest areas first of course... cap, pump, dampers.............you would think if it were pump, then it would affect other colors...............

would be odd for both dampers to go out at same time on one color...........
cap is possible but not likely either, just affecting cyan only........

might just have vapor lock in the head, you could open the valves and try to pull ink with a syringe from under the cap............

i guess electrical is possible.............................always go cables first(cheapest), head or mainboard is total last resort.............

Case

 

[Neil]

I've attached 2 syringes to the 2 tubes between the cap an pump.
I can push/pull (gently) on one of them and hear an air leak from around the cap.

My guess at this stage is a bad cap seal or tubes/joins under the cap...

 

[mustafade]

Similar problem occurred on my JV-33 and the problem was capping station aligment and I end up replacing couple of dampers as well. Once I did those voila back to normal.

 

[Case]

I've attached 2 syringes to the 2 tubes between the cap an pump.
I can push/pull (gently) on one of them and hear an air leak from around the cap.

My guess at this stage is a bad cap seal or tubes/joins under the cap...

For sure, sounds like a bad seal, do not pull ink without opening the valves first.........you either have to do this through the menus in maintenance mode or tape the valves open behind where the ink carts go in, inside the cover behind the needled that goes into the carts...

Case

 

[Neil]

Okay I ordered a new cap and have just fitted it.
That was the problem!

Now I see a lot of ink going through the drain tubes whereas before there was hardly any.

I guess that when both cyans quit at the same time, there must have been a small air lock or something just enough to impede the flow.
The pump wasn't able to pull the ink through due to the bad seal at the cap.

So now it's working again, thankfully.




Now, short story long:
It wasn't going to let me get off that easy.

For some strange reason, the right hand magenta channel dropped out completely whilst all the previous unsuccessful cleaning was going on.
Now after I installed the new cap, every other channel came back 100% but for that magenta which refused to print even 1 nozzle.

I hit it with about 10 cleanings and could see all the ink getting drawn through the tubes and flushed away - but that magenta just wouldn't budge!
Nothing at all.

How could this be?? I've never had any trouble with that channel before. Why now??

Note this wasn't the left hand side magenta that I'd previously swapped to verify the head was okay. That one was working fine.
This one was untouched.

Could I have dropped ink on a connection?
Could the damper suddenly become blocked?
Maybe the cap is out of alignment and not covering that side properly??

I had a look and it did appear that the cap wasn't sitting dead centre under the head. It needed to come over about 1.5 mm to the right.
So I made a shim and fixed it to the stop on the capping station so the head would sit back a bit.

That's gotta work now right?
Nope. Still nothing. Try a different size spacer. Nada.

So, I swapped the 2 dampers on the right side - cyan for magenta - to once again check the head.
1 cleaning had the cyan coming out of the magenta channel, but still no magenta coming out.
So it wasn't the head, thankfully, again.

When I had the magenta damper out, I noticed some sludge-like whiteish liquidy goo sitting on the bottom of the filter chamber in the damper.

Blocked damper perhaps??

So, having never attempted this before, I decided to pull both magenta dampers and flush them out.
I would have just swapped them for new ones if I had any - but being a Sunday and all....


Armed with a little knowledge gained from posters here, and the maintenance manual, I uncliped the dampers at the quick release connector. und removed them. Drew cleaning solution backwards through them until clean. I realised that pressing the circular valve in the damper allowed easier passage of the fluid.

After emptying the clean dampers I plugged them back in to the lines.

Now I could do an ink fill but decided to try another way of filling the 2 dampers.
I removed the back cartridge cover and taped around a magenta solenoid valve to hold it open.
Then stuck a sryinge with thin tube into the damper, held it upright, pressed the circular valve and sucked the ink in till it was (nearly) full.
I couldn't get all the air out....
Did that for both magenta's and plugged them in.

One more cleaning cycle.

Thinking: "If this doesn't work I'm comletely stumped".

Test print. Hooray! It worked.

Was it simply a strange co-incidence that the magenta chose that same day to stop working right after I'd resuscitated the cyan?
Who knows.
Cue the Twilight Zone music.


A couple of things to note:
I really don't recommend anyone to try this. It's fraught with danger and frustration.

Everything was unplugged, discharged, covered up and I was super careful with my every move.
Ink will drop out of the dampers so I covered the wiring and cables with vinyl to protect them.

But in the end, I now have a better understanding of the workings of this machine and can probably troubleshoot similar occurrances when they arise.

 

[Rooster]

When you swapped the dampers you created an airlock in the magenta channel. When you drew the magenta ink through the damper with a syringe you removed the airlock. That's the correct way to install a damper. They need to be pre-loaded with ink the way you drew the magenta into the damper with the syringe.

Good work and thanks for the update.