Remapping K7 Channel on 9890



This is John Dean in Atlanta. Hope all is well up there. I just joined this forum.

I’ll try to make this as short as possible. My Light Magenta channel went blank on my 9890 in the middle of a job. I’m using this printer for K7 Carbon for the last two years with no issues.

I talked to Jon via email and he sent me a video action procedure to remap the Shade #5 of K7 to the LLG channel that was not in use and had Piezo Flush in that channel. I switched out the inks by cleaning out the carts carefully switching those inks, and remapping the curves by cutting and pasting as the video described. I did that successfully.

After doing this and doing a couple of power cleans and nozzle tests I see that both the LLG and the LM channels are totally missing. Now that I think of it I had not seen a nozzle pattern recently in the LLG channel, but hadn’t really though about it because other than the first week I had the printer and did color with it, this channel has never been used and had a full cart of flush fluid in it always. Maybe there is an air bubble in that channel because it hasn’t been used in 2 years for anything. I rarely have to do any nozzle cleaning and if I do it was for one pair clean only. It has been a very easy to use system until now.

So, my question is: Since I do see the Yellow channel is functioning correctly with shade #7 in it, can I do this remapping text data procedure again with the QTR profile and put my #5 there in the Yellow channel, and put the shade #7 in the LM channel and hope that it eventually comes back? That would make it a K6 printer with hope of becoming a K7 printer again :slight_smile: .

I am wondering if there is some pressure connection between the LM and LLB channels ( they are side by side in the ink slots of the printer). All my other channels have functioned perfectly always. Wonder why these two decided to flake out together.

I only use this printer for matte K7 Carbon printing and can live with making it a K6 printer if I have to. I don’t think the shade #7 really does anything anyway.

But if I do that do I need to reprofile the paper curves?

Just want to make sure this will work before I clean out and change the carts again.

Any suggestions would be appreciated. Need to fix this and finish the job tomorrow.



{ As a footnote I have to mention that when I put the piezo flush in the LM channel initially to see if I could flush it out, that worked and the nozzle was perfect. I then put the shade #5 back in and printed out a lot of blank roll of paper with lm color and rob driver and it did that for two 36x36 purge images, no banding of the gray patter or anything, but then clogged again and went blank after the second print, at about where the ink fully replaced the purge fluid in the lines. In other words when the ink was put back in it eventually clogged again while the flush fluid was showing a perfect nozzle . I tried two different carts for this, a small one a large one, both were primed correctly and totally full. Go figure. Flush worked, ink didn’t. The ink is new from you guys. About 2 weeks old. The ink looks fine. Maybe the printer needs more pressure to pull ink through than the flush fluid?}


Hi John~

Your experience with the LM channel is very strange. I was thinking the ink cart might be restricting ink flow, but you ruled that out by trying two different carts. We haven’t received any other reports of flow issues with Carbon shade 5, or any other Piezography inks, so I don’t suspect the ink (though it is thicker than PiezoFlush). I’m sure you’re good at keeping the printer clean, regularly exercised, carts filled/primed correctly, and regularly agitated. Have you ever replaced the ink selector damper unit and/or wiper blade in this printer? It’s possible after two years of good results, some parts need to be replaced.

Yes, you can move the shade placement in your printer, and will need to re-map the curve files to match the ink shade you have installed in which color position. To eliminate shade 7, and move shade 5 to the Y channel, you can use “P2” curves as a base to edit. With P2 curves, matte curves use black in the black channel, and have a higher ink limit, and gloss curves use black in the yellow channel, and have a lower in limit for better gloss compatibility.

I have attached what I have for pre-made P2- Carbon curves for you (a few matte and glossy).

Please let me know how things go, if you have further questions, or there’s anything else I can help you with.
All the best~ Dana

Carbon (28.9 KB)


Hi Dana,

Thanks for the information.

Yes, it’s also odd that the LLG channel is totally blocked since I never used that channel with ink since the piezo inks were put in 2 years ago. After the initial fill it’s just been sitting there.

To get me through the jobs I"m working on I"ll switch the shade 5 to the yellow position and use your curves for this work as k6.

Then I will order some dampers and wiper blades for those channels and put them in.

Is that difficult? I really hate to work on any of these modern epson’s but I guess I need to try. Couldn’t make these channels any worse.

Do you or anyone have a video tutorial on how to do that safely?

thanks for the help,



Hi John~

Yes, I’m curious how long the LLK channel hasn’t been printing, as it should have still got exercised when you did cleaning cycles, and print on the nozzle checks…

No, we don’t have a tutorial on working on this printer, but I have seen helpful (and funny) videos on
For this model, the dampers are sold as one unit, called the “selector unit”. I just looked on, and see they have the 7890/9890 selector unit (part# 526) for $176.30, and recommend you also get two replacement ink line o-rings (part# 596) when replacing the selector unit. The wiper blade is part# 568, and costs $13.04. The wiper is VERY quick/easy to replace, and the selector unit is pretty easy, but takes a bit longer. Having a long neck #1 phillips screw driver with magnetic tip is helpful in this (and other) printer repair. I got one that has been helpful for working on other printers as well, and also got a magnetizer/demagnetizer to magnetize the tips of the screw drivers I use. Just be SUPER careful to not put the magnetizer near a computer, printer or other electrical device- I keep ours safely in a plastic drawer.
Get the repair manual for your 7890/9890 (we get manuals from for clear step by step instructions with clear photos to follow along.

Please keep me posted, and let me know if there’s anything else I can help you with.
All the best~ Dana :slight_smile:


Thanks a lot Dana for the links,

I’ll work on this next month when I can get to it. Hopefully it will clear those 2 channels. The quality of the nozzle pattern on all nozzles looks like new, except for those 2 that are totally missing. I’ll let you know when I do the work. For right now I’m going K6 with those curves.



You’re very welcome John. Please do keep me posted and let me know if there’s anything else I can help you with.

All the best~ Dana :slight_smile:


Hi Dana,

You and Jon were very helpful.

I’m up and running with K6 until one of these other channels opens up. I think it is odd that I lost two channels for no reason but this set up looks good and I might end up having to keep it this way.



We’re always glad to help!

I’m happy to hear you’re up and running with the K6 setup. Honestly, from my own experience and feedback I’ve received from other users, sudden drop out of channels isn’t uncommon for these printers- but I hope for your sake, that no more channels go!

Best regards and happy printing~ Dana :slight_smile: