Missing magenta channel on R2880

[Rhayader]

I'd like to share with the community a problem I'm facing with my R2880.

The printer has been working good for months, with perfect nozzle checks and nice prints, until I made the mistake of continuing printing even if the status monitor warned me that magenta ink level was low.
I tought the printer would have stopped printing if the level had dropped too low but this didn't happen. When magenta level reached 1% (read through the adjustment program), I decided to change magenta cartridge and a few others that were below 10%. All carts are OEM.

The first nozzle check after the new carts were installed showed no magenta at all and very few yellow lines. All other colours were fine.
I then run some head cleaning with inconsitent outcome. Sometimes the nozzle check got better, but never perfect, sometimes the magenta channel totally disappeared. Yellow channel was affected by these cleaning too. The best patterns came after some resting time from the cleaning. I also tried two different brand new magenta cartridges.
The behavour is similar to the one described by RiverRat01 in his thread about Epson SC-P600 but then ink system of R2880 is a lot simpler than that of P600 (no pressurization pump, tubing, etc).

Finally, after several runs of cleaning cycles and overnight resting, I got a nearly perfect nozzle check with only one missing magenta nozzle.
Thninkg the problem was solved, I ran another cleaning hoping to restore the missing nozzle. I was wrong: magenta completely disappeared againg.
I let the printer rest a coulple of days and I could get just a few mangenta lines back in the test patterns.
I then printed a 100% magenta flush page using QTR and observed that the few printed lines quickly disappeared after some printhead's stroke.
All other channels are ok.
I also performed two ink charge cycles through the adjustment program without any benefit.
This behaviour makes me think that the printhead is still ok but there is something preventing the ink to flow to head.

The wiper blade is clean and straight. The capping station is clean, too. I also diverted the two waste ink tubes into an external tank to check that the cleaning effectively draws ink out the cartridge. Everything seems to work correctely. This is supported by the fact that yellow and cyan, that are flushed by the same half of the capping station, are working good.

I tried to pull some air throught the magenza nozzles (reverse flushing) using a syringe without any trouble. Air flows under slight vacuum and magenta foam accoumulates in the syringe.
Using the same syringe I also pushed 1 ml of magenta ink through the nozzles with very little pressure and without any problem. This restored 50% of the nozzles. Ufortunately, after another cleaning cycle magenta was 100% dead again.

I'm frustrated...

The only things I haven't tried yet are soaking the printhead on a piece of paper towel saturated with cleaning solution and completely remove the printhead to try some more aggressive cleaning.

Any advice will be very welcome! Thank you!

 

[RiverRat01]

Just so you know, years ago, I have needlessly, accidentally, and permanently, destroyed a number of R2880s. Thus, my credentials indicate that my expertise is of limited value. You removed the air vent covering on the new cartridge?

 

[Rhayader]

Thanks for the advice RiverRat01. Yes, vent ports are open. I also tried using self resetting cartridges filled with OEM ink but the problem persists.
I'm now planning some more intense cleaning. Let's see how it goes...

 

[Rhayader]

Some updates on my struggle with my R2880.
I soaked the printhead overnight on paper towel saturated with Pharmacist's cleaning solution. This improved magenta channel but killed cyan which looked badly deflected.
I then alternated some more cleaning cycles with soaking on wet towel. The result was that most of the channels were dead at the end of this treatment.
Thinking that I destroyed the printhead, I tried to flush each channel with few ml of cleaning solution that I gently pushed through the nozzles using a syringe and a tube. I didn’t remove the printhead from the printer so I cannot tell if the solution can flow evenly through all the nozzles but surely it flowed under very little pressure. I remember that on a heavily clogged head of an old P50, I had to push a lot more to make the solution flow.

As a final attempt, I ran an "automatic nozzle check and cleaning". This wasted a lot of ink but restored all the channels except for a few magenta nozzles. I let the printer rest a few days than I ran another automatic nozzle check and cleaning. This apparently solved the problem as the nozzle check print after this treatment looked perfect.

Unfortunately, this is not the end of my troubles because now magenta prints blurred (or smudged) with a lot of dots sprayed all around. See attached scans of the nozzle check and of a pure magenta stepwedge printed using QTR. Scans are done at 1200dpi resolution.
The quality improves a bit reducing the print resolution from 2880 to 1440.
The only imperfection i can see is a slight deflection of the cyan vertical line and a separation of the two vertical lines at the interface between cyan and magenta; apart from this, the nozzle check looks very good to me so I don't understand what may be the cause of blurred of magenta.
Any idea?

 

[RiverRat01]

Rhayader. Don't give up! Be extremely careful with water falling. Are you using the 20 drop Pharmacist concoction? I suggest that you continue to ammonia fume the head. Ammonia is corrosive but, you don't have much to lose. Further, if you decide to remove the head and clean it off-board; I have suggestions to share. I am unable to view your attachments - page not found at my end. RR

 

[Rhayader]

I just use a solution made with 3% propylene glicol, 20% isopropyl alcohol and water. I stopped using ammonia after I have destroyed the head of my old trusty R2400.
Now, after just four days that the printer has been sitting idle, cyan and magenta are again clogged and deflected. Some lines in cyan pattern are overlapping and most magenta nozzles are not firing.
I've never seen this before. I suspect there is some ink gunk accumulated on the bottom of the head.
I think I will proceed in the next days either performing several cleanings using selfresetting cartdriges filled with cleaning solution or removing the head to see how it looks underneath.
In the meantime I'm looking for a cheap used R3880 or R3000.