Attempting to clear completely blocked M channel in 7880



Hi Dana

I’ve been running CC K3 inks in my 7880 for about a year now. Recently the M channel simply ceased printing, so ran several standard cleaning cycles, with no success. I got some M ink showing on some nozzles, occasionally (usually after the second cleaning cycle of a batch of five or so - I still have the prints if you want to see), but eventually, when I realised how much good ink was being used, I gave up and decided it was time to give the printer some TLC and replace the capping station, flushing box and dampers.

I ordered a set of carts and a gallon of PiezoFlush from you which arrived last week; yesterday I started the procedure with a flush first, so I don’t fill my new dampers with gunk, and I can report that although 7 of the 8 carts showed a drop in PF level of about 2cm, the level in the cart in the M channel dropped hardly at all (which was the result after all those cleaning cycles, too).

So, I’m thinking that the blockage is in the print head, or the damper - I guess I’ll find out as I continue to work. I dismantled the cover today, and found that the flushing box is really badly caked with dried ink; I’m surprised that the blockages in the head aren’t worse. Hopefully I’ll get a result after I’ve replaced all the parts, and done a head scrub if necessary.

All this is a preamble to a couple of questions:

  1. The parts provider did not have a wiper in stock, and they’re quoting about a month until they do. Is it feasible to transfer the old wiper to the new flushing box assembly until I can replace it? I read in the Service Manual that I shouldn’t touch the wiper with bare hands, and I get that, but can I handle it with gloves on, so I can clean it with PF?

  2. The Service Manual recommends that certain adjustments be made via the Adjustment Program after replacing parts - except it appears that the Program is only available for Windows, and I have a Mac. How critical are the adjustments? I get that some of them are counter resets for life expectancy of parts, but things like the Air Leak Check, which requires a special jig, I won’t be able to do. Do you do all of the recommended adjustments after repairs, or just some, or none?

As always, I appreciate your time. Thanks -


Update: pleased to report success in clearing the M channel. I’m getting a good nozzle check pattern; M channel is still printing with M ink, rather than PF, but this makes sense as the blockage would have prevented PF penetrating right through the line to the damper. Do you have any recommendations for clearing the M channel of ink and replacing it with PF without having to wage PF in the other 7 lines? Or is it an all-or-nothing situation?

Thank you so much for your fine products and the excellent tech support you provide via the articles on your site and this forum. I’ve just saved the cost of new print head!



Hi Nick~

Excellent news, I’m glad to hear you were able to get the M channel printing again! Did it return after changing the damper, or just after some manual cleaning?
Regular manual cleaning of the printer’s capping station, flushing box and wiper blade are important to keeping the print head clean and in good working condition, to get the best quality output and longest life from your printer. If you’re not already familiar, you can find our manual cleaning procedures here:

You don’t want to touch anything that comes into contact with the print head with your bare hands, because oils on your skin can cause problems with the print head. It’s best to wear rubber gloves when handling the print head or wiper blade. The capping station, flushing box, wiper blade and print head (and other internal parts) can be cleaned with PiezoFlush. I believe we have replacement wiper blades for your printer model, though they are not currently listed on our website, so you will need to call or email to order that part. You can email our sales manager (Wells) at

If you have PiezoFlush carts in all eight channels of your printer, then the best way to flush your printer is by doing an Initial Fill Cycle (which you can find directions for here: If PiezoFlush has made it’s way to the print head of 7 channels, but not in the magenta line, then you may only need to do 1-2 Power Clean Cycles to move PF the rest of the way thru the M channel.

It’s best to replace all eight dampers at the same time (the dampers and other parts should be replaced every 1-3 years, depending on use, and clean your printer regularly, as well as regularly agitate the ink cartridges to maintain in-suspension pigment for full/accurate density, and consistent output).

I have only used the Adjustment Program when changing a print head, and have never used it when replacing other parts. It’s important to carefully inspect dampers (and any part, for that matter) to make sure there are no punctures in the thin plastic membrane, or other damage, before installing into your printer. I have certainly had new parts arrive damaged, so it’s always best to inspect before installing to avoid headaches and frustration of dealing with a non-working part.

I hope this helps, please let me know if you have further questions or there’s anything else I can help you with.
Best regards~ Dana :slight_smile:


Hi Dana

As far as I can tell, the M channel was cleared after replacing the dampers [I]and[/I] performing a head scrub - which was mostly a head ‘soak’, leaving a pad moistened with PF under the head for about 3 hours, followed by some very light side to side ‘polishing’. I didn’t get a good nozzle pattern until after I’d performed two or three standard head cleans, but then - voila!

The flushing boxed was badly caked with dried ink. I’ll be inspecting and cleaning it on a much more regular basis from now on!

Also, I’m going to switch from auto to manual paper cutting for a while to assess the impact that’s had on the printer - once I got it dismantled, I found a [I]lot[/I] of paper dust inside. I’ve always removed this from the areas I could see and reach without dismantling, but I recommend to anyone that pulling the covers off and cleaning up regularly will really help prevent clogging issues.

Thanks for your advice re the Adjustment program. Although my 7880 is five years old, it hasn’t done [I]that[/I] much work compared to a commercial printer, so I’m content to keep working without resting the counters for the replaced parts.

Thanks agin


Regular cleaning/maintenance is important to keep any machine in good working condition, and lasting as long as possible.
Yes, paper dust and waste ink can create a nasty gunk that causes issues, so again- regular cleaning is important. Fine art papers will have more “dust”, but we primarily use heavyweight fine art papers in our studio, and have great results with all our printers, but also have a regular cleaning routine for both the printers and printing environment.

Best regards and happy printing~ Dana :slight_smile: