Clogged head, Epson 4900

For the last couple of months I’ve been trying to unclog my 4900. I had it setting too long without much if any use. Started with I’d say over 80% clogged. After a number of cleanings, both regular & powerful, most came clean. That gave me a lot of hope so i then tried the head soaking procedure with a couple of different solutions. Also replaced ink carts. Still could not get ANY test marks from the OR & GR channels.
I then downloaded the maint. software and ran initial fill, 2 times Both sides, 2 more times just the side with OR/GR. OR/GR are still both TOTALY clogged, nothing!!! I get 100% test marks on all the other channels. any ideas welcome TD

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Hi TD,

Are you by chance doing all this with outdated ink? EPSON oem inks have very short cartridge life according to EPSON (6 months once inserted.) A year probably OK - but you mentioned the printer has been sitting a long time. You may be just pumping agglomerations of pigment into it if your carts are 2 years or older…

Kind regards,


Thanks Jon
I’ve replaced all carts with new over the last couple of months, most with Cone Color.
all of those channels are printing a clean test pattern. The OR/GR have never printed anything. I find it interesting that the 2 are paired together
Thanks TD

Post a nozzle check - maybe they are delaminated. Have you seen what delaminated ink channels look like?

no, i’m not sure what I’m looking for


they look this:

no, not like that at all,
The whole block is missing. I’m working on getting a current test print to show you

this is what I’m getting for OR/GN

thanks TD

Was the INIT FILL drawing from the two carts like the others?
Is there air or ink in those two lines?

That pair has been like that from the very start.
several power cleaning and 4 INIT FILL cycles with new Cone carts

yes i understand

but my questions were whether the O and G ink carts are being drained by the INIT FILL like the others are or NOT?

And is there AIR or INK in the orange and green ink lines?

I can monitor the Ink carts visually, they are Cones.
But how would i check for air in the lines?
I’m turning in for the night, chat more tomorrow

Thanks again Tom

I was up late last night replacing a printhead in one of our P9000s. I feel your pain! But, this morning printing better than ever…and a large project with a deadline on this particular ink set in that printer.

I am trying to preserve the printers I have on the floor, while conserving the five I bought for long term storage in a warehouse. That is our strategy at Cone Editions so we can print with our own inks for another decade or more!

Do you know where your ink lines and ribbon travel from the carts to the print head? You should be able to release the cover and pull them slightly forward at the front to see if you can see orange and green ink or just white tubing or intermittent ink in the tubing…

If all is lost on your O&G, you can still turn your printer into a 9 ink Piezography Pro printer and simply use the 4900-Pro-K4 curves which do not use Orange and Green dropping the two Very Light Grays…



Good afternoon Jon,
First thanks for your time!
I would still like to pursue getting her revived because I can use your inks.
I was using your inks in the printer I had before the 4900.
I was able to check the ink lines and found no air spaces, solid color all lines.
as far as ink levels, seems as though the OR/GR didn’t show any visual level change where the others did.
what do you suggest for the next step?
Thanks TD

This means no ink is leaving the cartridge even during an INIT FILL which would be unusual unless you had not primed these two carts… or you did not remove the air vent plugs. It would indicate perhaps totally plugged up ink dampers in the ink exchange unit or ink lines… possibly less doubtful is the capping station can not get any ink from these during the INIT FILL - but you may want to look and see if that is clean… but it does not indicate electronically dead channels because INIT FILL uses suction not stimulus to move ink.

So my friend, you have a physics issue! Either the cart is not allowing the ink out or it can not travel through the ink line or the ink can not get past the ink dampers or can not get into the print head…

So check your vent, check your prime, pull the ink line off the ink exchange unit and see if you can draw through it, then if brave and not weak of heart remove the ink exchanger and google damper replacements… at that point you have taken care of everything backwards. Do those step by step not all at once.

Hopefully you left the air vent plugs in!



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Sorry all the plugs are out, and the carts are primmed.
So, i guess i’m looking for the ink exchanger unit, and dampers.
I’m assuming they are part of the head unit

I’ve Been trying to find some instructions for replacing the dampers, but haven’t found anything searching.
i have learned from searching for parts that the 4000 & 5000 have an unusual damper, it handles 2 ink lines.
That happens to be a pair i’m not getting any test pattern for. I’ve watched videos for other printers, But when i uncover the head I’m lost. It seems that I need to remove the ink exchanger from the top of the he’d before i can even remove the ink lines from it. Am I even close? And if I am, I’m not sure how.
Any references for videos or step by step with drawings would be of help.
Thanks TD

Go to and download the Field Service Manual for the EPSON 4900. It is about $20 and is profusely illustrated step-by-step to disassembly of this printer. To figure out how to take your ink selector unit apart to replace the dampers instead of buying a new one - check out on this forum 3880 ink selector unit rebuild that shows that process…

All of the repair manuals and service software are available for free from the Epson Wide Format users group here. This is the 4900/5000 repair manual.


It requires joining the group (free to gain access to the PDF).