Suggestions for clearing clog on 7890 / Epson Support Rant

[AndrewKelley]

My 7890 has a stubborn clog in the LLK (just part of a couple of lines). I've made a number of unsuccessful attempts to clear the clog, including printing and hoping it goes away, power and regular cleanings, the windex on paper towel trick, and some maintenance mode cleanings.  I'm afraid the printer is on its last legs.  But given the relatively light wear on the  printer (roughly 3K prints over three years), I'm hopeful that there is something else I might try before scrapping it. Suggestions?

Now the rant: I had a similar problem a year ago, and called Epson. The tech was extremely helpful. Asked lots of questions to diagnose the problem, and ultimately fixed it with a maintenance mode cleaning. Fast forward to today: the tech was extremely unhelpful. He made no effort to diagnose the problem or offer suggestions.  According to the tech, if I can't clean it with a power cleaning, then the head is broken. I asked him about maintenance mode. I don't think he even knows what that is. (Example: he told me that the maintenance mode cleanings are all the equivalent of a power cleaning, which I believe to be untrue.) In about fifteen seconds, he told me that the only option is an $1800 head replacement.  I can buy Canon iPF6400 for that price. Hmmmmm . . .

[Mark D Segal]

Don't rush to buy an IPF6400 - if you are going the Canon route it would be worthwhile looking into the new Canon Pro-2000 and make a deliberate choice. Returning to the Epson problem, if it's just one channel, give it one more try doing three or four cycles of [power-clean, print a page of only that colour, nozzle check]. If after three or four of those the problem has not resolved you may then be thinking of a printhead, which in effect puts the whole question of replacing the printer on the table. If you are proximate to on-site service it may be worthwhile having a COMPETENT technician look at the printer in situ once you have tried this and it fails.

[Royce Howland]

See the other thread on a 9890 head issue that's in discussion concurrently with yours. If your nozzle checks look like those of the OP in that thread, specifically in the characteristics I pointed out, I suggest the head indeed is dead. I've seen that specific failure pattern on 11880 heads, and x900 heads. I haven't run or worked with any x890 printers, but their heads are the same at the core, as far as I know. This type of failure on these heads is not related to printing volume or even age of the head, it seems to be able to strike pretty well any time.

Any form of cleaning is a reasonable approach if the problem is one that can be fixed by cleaning. The trick is diagnosing from whatever print flaws are visible, what the underlying cause is, or could be. Sometimes that diagnosis can't be made, and so we try various things to see what might work. My experience is the specific pattern of flawed nozzle check prints shown in the other thread is not a symptom of any kind of clog, air in the ink lines, pressure system failure, etc. but rather of a failed head.

And yes, I agree that Epson support is not too useful. (Also true of most other big companies these days.) We have a good Decision One tech in our local area and have called him out a couple of times to handle things I prefer not to do myself -- mainly just head replacements. No regrets in either of those instances. But mostly now I self-support. If research into a problem with any of our LF printers leads me to believe I can get parts and have a shot at fixing things myself, that's what I try first.

Modern LF printers are amazing when they work. Once they go sour, it's time to prepare to spend  more cash, or else take the time to roll up one's sleeves for some research and DIY maintenance. All in my opinion of course...

[Wayne Fox]

the windex on paper towel trick,

There is quite a bit of anecdotal evidence that the old windex on towel trick can actually damage the internals in the newer series of Epson heads.

[AndrewKelley]

Thanks to all for the very helpful suggestions and comments.

I looked more closely at the nozzle check pattern, and I suspect that what I saw is bad news.  In between the gaps is a pattern check line that is not oriented in the same direction as the other patterns. Sort of like this (though not so exaggerated as this ASCII diagram):
----------------
--- ------------
----  \ --------
---   --   ------
----------------
I assume that this is indicative of a problem with the head, rather than a clog?

[Royce Howland]

No, not necessarily. Although I'm just guessing based on the ASCII art this could be just a minor deflection caused by some crud on the head (or within the channel). One or more cleaning approaches might well resolve this issue.

A definitive example of head failure (IMO) is what's shown in the other thread. If you have taken a look at that, how similar or different is your situation to the patterns posted there? If you can post a closeup photo or scan of your printed nozzle check pattern, that might help suss it out a bit better...

[Wayne Fox]

I would agree, it looks like a nozzle deflection caused by dried ink on the surface of the head.  I usually try to soften that up by moving the head over a micro fiber cloth soaked in distilled water, and letting that soak for a few minutes or if it's available some of the cleaning solutions.  (I never use ammonia based cleaners like windex anymore).

it might take a few tries.

A single nozzle deflection is rarely visible in a print. although in the LK and LLK channels it can show as subtle banding.

How old is the printer?  I would pull the wiper and check it. If it gets crusty or worn it can leave stuff on the head like this.  You usually can clean the wipers pretty easily, but they're not too expensive to replace.

[JohnHeerema]

It's easy enough to change the dampers yourself, but I'd be surprised if they are the cause of the missing nozzles - the dampers filter particles out, but otherwise just deliver ink to the head. It's also easy enough to replace the head yourself, but I don't see it being worthwhile on a 79xx printer, as the cost would be a large percentage of the cost of a replacement printer.

If you've got gunk on the surface of the head, it's easy to use distilled water on a paper towel to clean it. Just initiate a wiper blade change in service mode, and power the printer down while the head is in the middle of its track. Soak a folded paper towel in distilled water, place it adjacent to the head assembly, and pull the head assembly over it (carefully, of course!).

Assuming that doesn't work, it might be interesting to send Epson Japan a copy of the receipt for your new Canon printer, along with a note written in Japanese explaining your decision!