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Author Topic: Clogged Light Black Ink on Epson 7900 (same line on each nozzle check pattern)  (Read 26705 times)

worldburger

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Hey guys,
So I have a 7900.  It's just out of warranty and I have gotten a clog in the light black ink which manifests on the same line of the nozzle check pattern after each run.  Sometimes it's the entire line and sometimes it's just 2/3's of all the steps in the line.

I've done multiple cleanings (regular, pairs, power), put it in maintenance/service modes and done CL2, CL3, and CL4 cleanings, and printed MANY nozzle check patterns.

The printer had previously been unused for a few months (but turned on and off to do nozzle checks and cleanings, occasionally) and prints had been done successfully in January (50+ sq ft).

I am near Indianapolis and I have a company scheduled to come look at it today but it's expensive (2hr roundtrip drive @$65/hr plus $145/hr labor) and they think it's the pump and ___ assembly which will run $250ish for a grand total of at least $500.

Then there's the reality that the printer had service in service where the printer was drinking ink for cleanings which just leaves a bad taste in my mouth.

Any suggestions on ways I might de-clog the printer before I commit to the service?  I do have some cleaning solution I had used before on my Epson 4000 which de-clogged just about any problem I ever had.

David
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Mark D Segal

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Have you called Epson tech support to discuss the issue? Regardless of the warranty status, they are normally responsive and helpful, and they may be able to answer these questions before you spend all that money. Did you bring these defects to their attention while the printer was still under warranty? If so, I wonder whether that would give you grounds for repair support on their account, as an unresolved issue from during the warranty period, but I'm not certain of the legalities. It would be good to get a second opinion on whether a defective pump assembly could cause nozzle drops only specific to the part-row you mention. This sounds weird, even though I'm no printer tech. I would surmise that a problem with a pump assembly would show more pervasive issues.
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Mark D Segal (formerly MarkDS)
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Randy Carone

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If only one color is problematic it could be the damper for that ink. Doubt it is the pump if only one line is starved for ink.
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Randy Carone

Mark D Segal

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If only one color is problematic it could be the damper for that ink. Doubt it is the pump if only one line is starved for ink.

What's a damper? I'm interested, because I'm seeing rather unique Cyan nozzle check gaps on my 4900 if not used for more than a couple of days.
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Mark D Segal (formerly MarkDS)
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Randy Carone

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The damper is a small plastic ink reservoir just above the print head that holds a small amount of ink. I just tried to copy a page from a Service Manual pdf with no luck. If you Google 'ink dampers' you should be able to find a picture of one. Most users of Mutoh, Mimaki and Roland replace dampers fairly regularly. They all use Epson heads, but the dampers are not the same as on Epson aqueous printers. If you find a pic it will be immediately obvious what function they perform.
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Randy Carone

Mark D Segal

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The damper is a small plastic ink reservoir just above the print head that holds a small amount of ink. I just tried to copy a page from a Service Manual pdf with no luck. If you Google 'ink dampers' you should be able to find a picture of one. Most users of Mutoh, Mimaki and Roland replace dampers fairly regularly. They all use Epson heads, but the dampers are not the same as on Epson aqueous printers. If you find a pic it will be immediately obvious what function they perform.

Thanks Randy.
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Mark D Segal (formerly MarkDS)
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deanwork

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Dampers are the small filters that filter the pigments as they pass from the ink lines going to the ink carts to the print heads. Often what ends up clogging dampers is residue from cotton rag papers as well as impurities in the inks themselves.

Each ink cart has its own damper which is attached to the bottom of the print head. With piezo printers like Epson, Roland, and Mimaki, dampers are often the first mechanical thing to check when head cleanings can't solve the blocked nozzles. Dampers are cheap and fairly easy to replace and are available for just about every Epson printer that has been made. If you run a lot of cotton paper you should change them more often. Normally you take the head cover off and you can access them fairly easily.

I believe Roland recommends changing out their dampers regularly and unlike Epson, they make it very easy to accomplish.

Changing the dampers won't help you if you have defective pressurized ink carts though.

john
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Mark D Segal

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Thanks for the added clarification John. I should think on a new printer one would not expect trouble from this source, unless it is somehow defective out of the box, if that's possible.
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Mark D Segal (formerly MarkDS)
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Alan Goldhammer

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Thanks for the added clarification John. I should think on a new printer one would not expect trouble from this source, unless it is somehow defective out of the box, if that's possible.
And it also should not be problematic if you do a lot of printing with IGFS (which I know you do ;)) since there is not much dust on that paper relative to a number of others.
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Randy Carone

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Clogged dampers may be an occasional problem, but the most common damper problem is a pinhole that allows minute amounts of air to seep into the ink line, resulting in a bad nozzle check that can be temporarily alleviated with cleanings but will return shortly after.
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Randy Carone

Mark D Segal

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And it also should not be problematic if you do a lot of printing with IGFS (which I know you do ;)) since there is not much dust on that paper relative to a number of others.

Right, and I wonder also how dust would get into the ink supply chain between the cartridge and the print-head. I thought that system would be closed from anything entering from the outside.

Mark
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Mark D Segal (formerly MarkDS)
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Mark D Segal

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Clogged dampers may be an occasional problem, but the most common damper problem is a pinhole that allows minute amounts of air to seep into the ink line, resulting in a bad nozzle check that can be temporarily alleviated with cleanings but will return shortly after.

Ahah, this starts to sound like something relevant to my issue with the Cyan channel. Perhaps I should re-discuss with Epson if I see it persisting.
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Mark D Segal (formerly MarkDS)
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Farmer

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Hmmm, not sure how a damper would get a pin hole in it, Randy. Cracking can occur (during transport or usage over time) but it would have to be a pretty specific hole to let air in, since dampers are one of the places air can actually escape/bubbles clear/settle.
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Phil Brown

Randy Carone

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In the 12+ years I have sold printers, small holes in dampers has been the most common problem with ink delivery. I don't know how the holes are generated - I used the term 'pinhole' loosely - but they do occur. Maybe it is poor quality injection molding, poor quality plastic raw material and small breaks in the ink line where it connect to the damper. Some dampers have an O ring that seals the assembly. I have seen splits in the O ring that have been the source of air bleed but I don't know if all Epson dampers/selectors have the O ring component.
« Last Edit: April 21, 2011, 02:00:46 pm by Randy Carone »
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Randy Carone

Garnick

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The damper is a small plastic ink reservoir just above the print head that holds a small amount of ink. I just tried to copy a page from a Service Manual pdf with no luck. If you Google 'ink dampers' you should be able to find a picture of one. Most users of Mutoh, Mimaki and Roland replace dampers fairly regularly. They all use Epson heads, but the dampers are not the same as on Epson aqueous printers. If you find a pic it will be immediately obvious what function they perform.

The "dampers" on the X900 series print heads are actually quite different from those on older models. Not sure about the X890 series, but I suspect they have a similar arrangement. On older models each ink line had a separate damper which fed the ink to the print head. On the X900 these are actually called "selectors". There are two ink selectors, attached to a unit(board), which in turn is attached to the back of the print head after it has been installed. Each selector has six ink feed connections, one of which is not used, obviously. Also, each selector receives ink lines in the same order as on the control panel. I've had two replacement heads installed on the 9900 and have been very attentive during the procedure, asking questions along the way as well. I also have the service manual and I'm now looking at it as I write. I believe each selector can be replaced individually but I'm not certain about that. Actually, I imagine the whole assembly(both selectors and board) would be replaced as one unit. That was not one of the questions I asked.

David,
Concerning the warranty issue, I was told by a tech at Epson that they usually have a bit of a "grace period" after the warranty has expired if one is having severe problems, especially if there's a record of previous issues with the printer. This also applies to those who might have planned on extending the warranty but had let it expire without realizing it. I recently extended the warranty on the 9900 because of the issues I've had and I'm glad I did. I am presently awaiting another service call due to a problem I noticed after the last head placement, which was about three weeks ago. Banding in the PK and what appears to be a situation in which the printer is not printing at the resolution I have chosen in the driver. I quite often print at 720dpi when the image allows and that is now looking more like 360 since the new print head. The extended warranty on these printers is NOT inexpensive, but I consider it an important part of doing business. Another insurance policy of sorts I suppose. I would suggest an extension might be the next step if you are still having problems that you can't seem to remedy.

Gary
« Last Edit: April 21, 2011, 01:23:46 pm by Garnick »
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Gary N.
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Ernst Dinkla

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In the 12+ years I have sold printers, small holes in dampers has been the most common problem with ink delivery. I don't know how the holes are generated - I used the term 'pinhole' loosely - but they do occur. Maybe it is poor quality injection molding, poor quality plastic raw material and small breaks in the ink line where it connect to the damper. Some dampers have an O ring that seals the assembly. I have seen splits in the O ring that have been the source of air bleed but I don't know if all Epson dampers/selectors have the O ring component.

With the older models: The seals of the damper connectors are the most likely place to let air in or with enough ink pressure ink out (seldom). The membrane (most likely PET) thermo/ultrasonic welded on the polyethylene damper house could have a leak at the weld, cleaning them with a syringe had that risk of pulling them apart there. Older dampers showed less flexibility in the membrane and the small stainless steel spring inside could in theory puncture the membrane in time. The membrane is there to equalise ink pressure on feeding and demand and adapt the ink pressure to the atmospheric pressure, at least on the the older Epsons including some pressurised models. It could be that it changed in newer models and another ink pressure control is used.

It wouldn't surprise me if the new damper model includes a sensor that actuates a valve in the ink line when the ink pressure/feed near the head drops, the opened valve to fill the ink buffer again. Something like that existed on the 10000 model but there internally in the head assembly.

With OEM carts the risk to get filth in the lines in negligible but pigment settling (say coagulation) in the ink can build up a barrier on the damper's sieve in time or with infrequent printer use. Inks have improved though.

Air in the head shows when the bad nozzles change in quantity and place. Frequent cleanings may not help at all, sometimes a night's rest does more. Thermal heads suffer less of air as the nozzle channel is less complicated and the thermal pump can still function with some air enclosed, piƫzo pumps need fluid to create the pumping action, any air there will just act as an air spring and the ink isn't pumped.

met vriendelijke groeten, Ernst

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/
« Last Edit: April 22, 2011, 02:48:29 am by Ernst Dinkla »
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worldburger

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So I called Epson Pro support again, they sent out a notification to Decision One (who had done the service call 1.5 years ago on this printer).  They gave me an estimate.  $450ish incl labor for the pump and cap assembly repair.

As this is a documented issue I've had, Epson said I could talk to customer service about reimbursement or them covering it.  I'll call them tomorrow about it.

As far as maintenance I can do myself, what is to do with the dampers?  Where do you buy these?  Is there anything else I can do to try and fix this myself?  On my 4000 I'd just put some cleaning solution in a syringe and pump some onto the place the print head sits when it's parked, but I don't even know what that'd be on the 7900 because there seems to be two places it goes when it parks.  Ideas?

Thanks (and stumped),
David
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Mark D Segal

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So I called Epson Pro support again, they sent out a notification to Decision One (who had done the service call 1.5 years ago on this printer).  They gave me an estimate.  $450ish incl labor for the pump and cap assembly repair.

As this is a documented issue I've had, Epson said I could talk to customer service about reimbursement or them covering it.  I'll call them tomorrow about it.

As far as maintenance I can do myself, what is to do with the dampers?  Where do you buy these?  Is there anything else I can do to try and fix this myself?  On my 4000 I'd just put some cleaning solution in a syringe and pump some onto the place the print head sits when it's parked, but I don't even know what that'd be on the 7900 because there seems to be two places it goes when it parks.  Ideas?

Thanks (and stumped),
David

Two points here, both of which point to doing nothing:

(a) no clarity on what the cause of the problem really is;
(b) if you are into a discussion with Epson about them covering the issue, don't muddy the waters by tinkering with the machinery yourself.

My two cents-worth.
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Mark D Segal (formerly MarkDS)
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Garnick

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So I called Epson Pro support again, they sent out a notification to Decision One (who had done the service call 1.5 years ago on this printer).  They gave me an estimate.  $450ish incl labor for the pump and cap assembly repair.

As this is a documented issue I've had, Epson said I could talk to customer service about reimbursement or them covering it.  I'll call them tomorrow about it.

As far as maintenance I can do myself, what is to do with the dampers?  Where do you buy these?  Is there anything else I can do to try and fix this myself?  On my 4000 I'd just put some cleaning solution in a syringe and pump some onto the place the print head sits when it's parked, but I don't even know what that'd be on the 7900 because there seems to be two places it goes when it parks.  Ideas?


David,

From what I've seen during service calls on the 9900 and in the Service Manual and Field Repair Guide, it would seem that there are few areas of these printers that are easily accessible to the user. As an example, to access the pump/capping station and wiper blade for removal on the 7600, it was a rather simple matter of removing the right end cover. To reach that point on the 9900 requires a much more time consuming and complicated procedure. And of course the pump/cap station assembly for the 9900 is also considerably more sophisticated. However, once there I don't believe the installation is much more involved than on older models. It's my opinion that this may very well be the easiest of all components to replace on the X900 series printers, and perhaps ironically, one of the most important. Also, it  would seem to be one of the lesser expensive parts to replace. However, one must have access to the proper manuals before attempting this procedure. As the last tech to work on my 9900 said, "my goodness, there certainly are a lot of screws to be removed". Of course I am quoting from memory and not verbatim. However, that statement did not instill in me a lot of confidence in his knowledge of this printer, as I have stated in a recent post on this forum. I hope you have some good luck with Epson concerning this matter. Also, you should consider calling Epson after the service has been completed and plead your case for replacement of some of the ink you have wasted trying to solve this matter yourself. They are usually quite compliant in that regard, especially in warranty situations. Another reason to consider a warranty extension, especially for these models.

Good luck and keep us "posted"!

Gary
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Gary N.
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Thelo

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I've done multiple cleanings (regular, pairs, power), put it in maintenance/service modes and done CL2, CL3, and CL4 cleanings, and printed MANY nozzle check patterns.

Have You tried supersonic cleaning in service mode?
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