Epson L850 - Head Clogged or damaged?

[kklc]

Hi, I need an opinion of someone experienced in head topics. Test print after head cleaning is perfect showing no issues, but when printing photo there are some issues. Tried aligning, cleaning etc. and... In attachment you can see BRS Print Test Pattern from ADJPROG that shows very detailed each nozzle. As you can see C and M On the bottom they are ok at 100% coverage bo has issues on lower coverage.

So the question is... is this head damaged and there is no help for that or it is nasty clogged?

 

[Ink stained Fingers]

Could you please post the nozzle check as well. What type of ink are you using - OEM or 3rd party refill ? How much did you print so far - the nozzle check should tell.

 

[kklc]

That's odd, that print was perfect when I've tested if week ago. But... some few more info:
OEM ink. Counter is not accurate, why? Because this is a 2nd head. The first one had the same issue but it was worse, more like on the OLD L850.jpg.

the 1st one I've tried to flush even manually, it was flushed by the cleaner by syringe couple of times, then it was over 24h in that cleaner then again flushed but it did not change anything, so i've went hardcore and tried the same with IPA and after ipa the cleaner to not dry out the head. and it did not help.

then i've bought on amazon 5 cheap heads and only one of them was almost ok (the one from the 1st post).

Now I'm in a point that I don't know what to do. Try more or leave it and buy new printer. I could try ultrasonic cleaner but I feel it won't help either.

 

[Ink stained Fingers]

I'm running a L805 which uses the same printhead, and I'm at 56 000 pages with the first printhead. It could be that the dampers - the cartridge inserts in the printhead - are clogged and don't let enough ink passing. There is a litle wire mesh filter inside which clogs up, and there is no simple way to clean them. But such dampers are easily available as a spare part via Aliexpress from China. The ink flow is restricted, it's enough for the nozzle check but not for the other color patches with more nozzles firing at the same time.
The dampers should not be filled up completely with ink but somewhere between 20 - 70%, an air bubble should remain in the damper. Since you did already that much cleaning I don't see that more cleaning would fix the damper problem.

 

[kklc]

here or here?

 

[Ink stained Fingers]

here or here?

No, the ink tubes connect to dampers, white cartridge like inserts into the printhead carriage, and the ink passes through the dampers and the filter to the ink connectors at the printhead - these should be replaced

dampers like these here - but there are more offers

https://de.aliexpress.com/item/1005...=scene:pcDetailTopMoreOtherSeller|query_from:

 

[kklc]

oh this ones. but... one of the faulty heads that I've tested had perfect magenta and cyan but black and yellow was so clogged that I give up and send it back. so to me it looks like this part is ok.

 

[kklc]

I'll try to swap colors just for test to be sure

 

[kklc]

Swapped C with LC and M with LM and no effect, so dampers are not the problem. That bring us to conclusion that the head or flow in the head to be specific is faulty.

 

[Ink stained Fingers]

It is my understanding that the problems - misprints - happend with sveral printheads in a row which still let me think that the problem is with the printer somewhere and not with the printhead(s) in the first place. Could it be that the tubing is somewhere squeezed on the way from the ink reservoirs to the printhead ?