Epson 4900 - Print Head Or Dampers?



Epson 4900 printer 2 years plus old. Low print volume 600 to 1000-8x10 Nozzle check print out has Pk with 30% if the lines missing. On LC 7 lines are missing. VLM only 4 lines are missing. All others are 100%. Same results on print test after changing to matt black. I tried 1 or 2 cleanings regular and or power cleaning. 10 new ConeColor inks and one epson LLK. How do you know if it’s the print head that is bad, or need to change Dampers?


Hi SamLip~

It’s hard to know for sure at this point, but I will try to help you trouble shoot your problem and get back to happily printing. Unfortunately, problems like what you’re experiencing are very common with this model, though we have had quite a few reports of success from people in your situation who have fixed their printers with our help, so there’s hope :slight_smile:

Generally, when the exact same nozzles are missing after doing cleaning cycles and manual cleaning, this usually indicates a blockage in the print head. If the missing nozzles move around after cleaning, then this is more likely to be restricted flow caused by build up in the damper(s). If the exact same nozzles are missing in the black channel after doing a black ink change, then I suspect you may be dealing with a blockage in the print head- as the two blacks have different damper channels, but share the same print head channel. The wiper blade also plays a big roll in the cleanliness and function of the print head. The 4900 is a very different beast compared to the previous models that I have a lot more experience with, and has MANY more sensors and mechanical parts that increase the factors when trouble shooting problems.

What is the humidity in your printing environment? If your climate is too dry, it will certainly cause clogging and flow issues. We follow the industry standard, and maintain humidity levels between about 40-60%. I find 35-50% is excellent for the best results with your printer, inks, and papers.

I Hope this helps. Please let me know if you have questions or there’s anything else I can help you with.
Best regards~ Dana


Yeah, I am experiencing similar problems.we maintain humidity and temperiture all the time. for us, nearly the entire of the pkmk channel was missing with no change after cleaning or switching blacks–UHT OH! Could be the print head! Got a new selector unit, and it fixed it for about two weeks flawlessly, then all of the sudden,it drops out in the whole middle section of pk and many scattered nozzles missing in cyan. Again no change cleaning. I saw walker said that the selector unit must be changed in tandem with the pump cap… Could that be it? Is it worth investing in one ? The printer was quite new when we got it with no issues, and I’ve been vigilent about cleaning and general maintenance .



Yes, dampers that are clogged make the cleaning pump go funky and vise-versa.

The two have fundamental design flaws that combine to make the printhead print with air in the nozzle when one or both units get funky. This air then causes irreversible nozzle shorts in the head and thus: dead head syndrome on the x900s.

I assume you haven’t actually printed anything with the PK channel in that sort of shape, so a cleaning assembly should fix things at this point.

Possibly a different PK (or OEM) cartridge too just to rule out any variables during this switch.

all the best,