[Uz27]

Hi guys!
The same problem again - ink is not coming thru the lines.
Last time it was a capping station. This time is something else, and I have no idea what it is.
Changed capping station, dumpers, and printhead- still the same problem.
So my question is- do Epson-based printers (Epson 3880 in my case) push ink to the printhead from the cartridges, or is it pulled by dumpers/printhead?
If anyone knows the answer -please help!
Thanks!

 

[NoXid]

It is siphon flow to the print head. The piezo head ejecting ink is what ultimately moves the ink. But the capping station can suck ink through the head to during cleanings or when air might have been introduced into the system, like when changing carts. If the hose that provides suction to the capping station has a leak, then the printer may not be able to clear air from the lines and restore siphon flow. There is probably a separate hose to each segment of the capping station, so one for what would have been the K channels and one more for the color channels. A cracked "ink spike" thingy that the dampers are impaled upon could also cause a siphon break, but would affect just that color.

 

[Uz27]

It is siphon flow to the print head. The piezo head ejecting ink is what ultimately moves the ink. But the capping station can suck ink through the head to during cleanings or when air might have been introduced into the system, like when changing carts. If the hose that provides suction to the capping station has a leak, then the printer may not be able to clear air from the lines and restore siphon flow. There is probably a separate hose to each segment of the capping station, so one for what would have been the K channels and one more for the color channels. A cracked "ink spike" thingy that the dampers are impaled upon could also cause a siphon break, but would affect just that color.

Thank you.
I'm getting lost in it
Already changed ink lines, dumpers, and capping station and printhead. Still the same result :-( It does not push/pull ink thru the lines.
Checked with a syringe that all lines and dumpers are not clogged, and ran a cleaning solution thru all of them. Waterfalled the old, and new printhead...
Each part by itself allows ink to pass. But when connected together - no ink coming thru.

Actually not sure what to do next! I think I changed everything...

 

[NoXid]

Hmmm, so say you've got the head and dampers primed with ink, will it then print some ink for like a nozzle check? If not, I'd check the ribbon cable and its connections. With ink primed into the head and dampers, the head should be able to print some of that ink. Even if there were an obstruction or air in the lines, it could print the ink in the head. If it can't do that, the piezo channels aren't firing.

 

[TABOB]

So my question is- do Epson-based printers (Epson 3880 in my case) push ink to the printhead from the cartridges, or is it pulled by dumpers/printhead?

This printer has a pressurized ink system (pump in the photo), so the answer is both.

During printing the printhead is generating vacuum, causing the one-way valves inside the dumpers to open and ink flows through.
During cleaning operation however, the capping station pump is doing the work, sucking ink through the nozzle plate.

 

[Uz27]

Hmmm, so say you've got the head and dampers primed with ink, will it then print some ink for like a nozzle check? If not, I'd check the ribbon cable and its connections. With ink primed into the head and dampers, the head should be able to print some of that ink. Even if there were an obstruction or air in the lines, it could print the ink in the head. If it can't do that, the piezo channels aren't firing.

After I changed the lines and dampers- the ink is not coming to the dumpers. Since the lines are clear- I can see how it slowly moves toward the dumpers each time that I turn the printer on and the air pump kicks in.
But it moves extremely slow. Maybe an inch after each turn-off/turn-on cycle.
And before I introduced ink into the system - I checked all items separately with air. So air comes thru all the "ingredients" of the system. Air passes thru ink lines, dampers, and the printhead...

Can printhead be a problem although it is passing air thru, and waterfalls beautifully? (as this is the only part that isn't brand new. I pulled printhead from a used Epson 3880)

 

[Uz27]

This printer has a pressurized ink system (pump in the photo), so the answer is both.
View attachment 274846

During printing the printhead is generating vacuum, causing the one-way valves inside the dumpers to open and ink flows through.
During cleaning operation however, the capping station pump is doing the work, sucking ink through the nozzle plate.

I guess I can change the pump...
But somehow I don't think that this is the problem. As when I'm running the cleaning (regular and extended) ink is still not coming thru the lines. And If the ink is supposed to be pulled from the capping station at this point - then it most likely it is not an air pump...
But then I'm out of ideas. Besides ordering all new parts again.
All the parts that I changed are new besides the printhead which I took from the used Epson 3880. But the printhead passes air thru (checked with cyringe) and waterfalls beautifully. So I'm not sure if it's the problem.

 

[TABOB]

After I changed the lines and dampers- the ink is not coming to the dumpers. Since the lines are clear- I can see how it slowly moves toward the dumpers each time that I turn the printer on and the air pump kicks in.

Everything is probably OK
Just pull the ink trough the dumpers with a syringe until the dumpers are full, then put everything back and start the printer.

 

[Uz27]

Everything is probably OK
Just pull the ink trough the dumpers with a syringe until the dumpers are full, then put everything back and start the printer.

Well - it didn't help
It took a while to fill the dumpers as ink in the tubes "fought" me (I never tried to pull ink thru the lines with dumpers connected, so I'm not sure if this is how it's supposed to be, but I feel a lot of back pressure pulling ink).
When dumpers filled with ink I connected the assembly to the printhead, ran a regular, and then "power" clean.
It does not "spit" ink to the capping station. The sponge there is white - so no ink coming thru.
And this is strange to me, as this printhead waterfalls beautifully!

Any ideas?

 

[NoXid]

This printer has a pressurized ink system (pump in the photo), so the answer is both.
View attachment 274846

During printing the printhead is generating vacuum, causing the one-way valves inside the dumpers to open and ink flows through.
During cleaning operation however, the capping station pump is doing the work, sucking ink through the nozzle plate.

Cool.

Where is the pressurized air introduced into the system? I imagine, but don't know, that it would be sent into the carts through a second port. So the carts themselves would not have a vent port open to atmosphere, as carts for smaller desktop printers do. I mention this because it almost sounds like a case of leaving the vent plugs in the carts ... except I presume that these wouldn't have vent plugs in the first place

 

[Uz27]

UPDATE.
I think I managed to fix it!
At least it prints now... Made 6 prints now. All came out good.
What I did:
I changed the air pump, capping station, cleaned the ink lines, replaced the dumpers, and changed the small motor that sits on top of the dumpers.
Not sure what exactly fixed the problem, but it is working now.
Thank you guys for your ideas!

 

[TABOB]

Where is the pressurized air introduced into the system?

The pump is pressurizing the carts, and there is a bag inside containing the ink.
A good system because the pressure is kept stable regardless of ink amount or altitude, BUT when the pump fails the vacuum prevents ink flow.