Full channel dropout after cleaning adjacent channel in 7900

My 7900 (running a K5 Cool/K4 Warm Piezo Pro setup) has developed a troubling nozzle drop-out pattern. I’ve been printing on this 7900 (and also a P9000) for quite a while and I’m pretty familiar with EPSON nozzle failure symptoms and causes but this one has me stumped.

First, all the symptoms are on carts/channels in the LEFT ink bay. Here’s a typical scenario:

  1. Fire up printer to start a printing session
  2. Run nozzle check - missing one or two adjacent nozzles on bottom row of Orange channel, and one nozzle on bottom row of Yellow channel. Everything else is good except for delaminated Green and K channels which I’ve mapped out.
  3. Reboot printer into Service Mode, run CL1 pair clean on Y/LLK nozzle pair, run CL1 pair clean on OR/GR nozzle pair.
  4. Run nozzle check - Orange channel has completely dropped out

At this point, it takes several more cleanings and perhaps a CL2 or CL3 to get the Orange channel back. I have also seen a few cases where the Orange channel is completely gone after doing a print; i.e. all nozzles were good when the print was started, but a nozzle check after the print shows Orange completely missing.

It’s not clear to me what is causing this. Could it be:
a. Bad LEFT ink bay? I mention this since it seems it is always the adjacent Orange that drops out when I clean the Yellow.
b. Ink starvation?
c. Damper issue? The Ink Selector was last replaced in July 2014. I realize the Ink Selector should be replaced about every 2-3 years, but I haven’t been using this printer heavily.
d. Cleaning station issue? Pump/cap assembly was replacedin January 2017 when I converted printer to PiezoPro ink

Because of two delaminated channels already (Green and K) I’m evaluating whether it will be cost-effective to fix this dropout issue.

Any ideas what is most-likely causing this dropout behavior?

So the orange is part of the green/orange channel pair. Because green is de-laminated, the orange channel shares the same “lamination pad”. While I don’t think it’s exactly de-lam that is causing the issue, the orange certainly will be the next one to go.

What I think is actually happening though is a combo where the cleaning unit is not making good contact w/ the head and the damper is dropping full air into the channel every once and a while. This can cause the full channel drop + clean + recover thing. I’ve seen it and replace of the ink selector (dampers) and cleaning unit generally fixes it. There is a cleaning unit adjustment in maintenance mode as well which changes the contact pressure of the cleaning unit agains the head (miss-aligned cleaning unit is a main cause of de-lamination by the way).


Some results I can report, and a few additional questions:

I replaced the Ink Selector and that has solved the Orange channel dropout.

However, my Cyan channel has now started to delaminate. So this leaves me now with 7 working channels on this head. I had already given up Photo/Gloss printing and was printing matte only with K5 Cool / K4 Warm before the Cyan channel started acting up. At this point, I’m pretty sure I’m done with the 7900 (unless I can find a cheap replacement head with perhaps a single missing channel). I may also be done with Piezography, but before I go there I have a few quick questions:

  1. Is there any currently shipping Epson printer (any size) that is usable with Pro ink in a MINIMUM configuration of K5 Cool / K4 Warm AND both Photo and Matte media?

  2. Same question as above, but matte only?


The P7000/P9000s


OK, that’s good to know. When I had looked previously at your P7000/P9000 products on the web site it appeared to me that you were supporting only K4/K4 with Pro ink (i.e. there were no ink kits that included Very Light Cool or Warm and I had earlier seen that Orange/Green chips were not available). But just checking now it seems you do have the Orange and Green chips, and presumably one can order individual Pro inks as needed which would allow either K5/K5 or K5/K4.



Only think out of stock right now is WT-DG-700 (warm dark grey 700mL) but 2x 350mL bottles will do the same.