9900 and ink switching issue--clogs

[Paul2660]

I have used my 9900 now for almost 4 years and it's been a good printer.  I did have a head replacement in year 3, under warranty but that was due to some other issues, non Epson.

However, one issue I see all the time, and really have since day one, is clogs that seem to form after an ink switch. 
The vast majority of my work, is done with PK ink, however I will take on canvas jobs where the owner needs a matte canvas, planning to coat it later.  I also will put some of my work on matte papers. 

So what happened today is a great example and why I feel that one of the greatest weaknesses of the Epson 9900 family is the ink switch.

This morning I started out with 25 large 20 x 30 and 24 x 36 paper prints.  The ink was set to PK and before the job I had a perfect Nozzle check, and during the job, 1/2 way I checked again, 100%, at the end of the job, 100%. no fall outs or deflections. 

I then switched to matte ink, printer goes through the process of the ink swap, and on completion, before anything was printed, the printer gave the message it had detected clogs.  OK, go figure. 

I did not turn off the print, print anything, nothing, just ran the ink swap out process, which should move PK, MK and LK or LLK (I can't remember which of these is used in the swap)  but now I have the following clogs (breaks in the nozzle pattern)

2 in separate spots in the MK channel, 1 deflection and 1 drop out in LLK, 1 drop out in green, and 1 drop out in LCyan. 

Sure, not a show stopper, but you can be assured that on a fine matte paper, these clogs will show up as fine banding, and on a test strip, they did. 

Next step, drop into Service mode and run CL1 level cleans on the MK, LLK, Green and Light cyan.  After that all clean, and I proceeded to make the matte print run.

But, this is pretty much the same thing that happens to me each time I swap, if not in the PK to MK, then coming back from MK to PK.  I personally don't feel that I had dirt or trash on the print head as before I commenced the PK to MK swap, I had a perfect nozzle check.  So the question is what happens here?  I feel it's something in the pizeo electronics instead of a physical clog as I can't see how a swap would induce a clog.  So from my 4 years of use, this part of the Epson Technology is pretty much flawed, may just be my printer, but it's done this from the 1st time I swapped ink.  In fact the ink swapping is why I learned to come up in Service mode, as if you let the printer try to clean this, it will take a lot more ink in normal mode and if you try a pairs cleaning in normal mode, you only have 2 levels, medium and high.  I can usually get the gaps out with a CL1 level cleaning in service mode, it's just the pain of shutting down, and coming back up in Service mode.

So, I would say, if you are looking at this technology and plan to make use of the MK and PK inks consider Canon's large format or the Epson 11880 which allows you to keep both blacks online.  I just don't see it working that well, again at least on my printer.

Paul

[davidh202]

I have posted about this on other threads Paul. It appears to be a common problem I experience also, exacerbated if there are any carts that are in a pretty low state. The switch can cause a back suction in the nozzles, actually draining some ink from some nozzles. It's all about the pressures in the carts and the lines during a switch, and which ones are the weakest in the chain. That is why this printer series is programmed to do an auto clean after a switch, to try and re pressurize and refill those missing nozzles. Sometimes that initial cleaning isn't enough. What you see in the nozzle check print outs are nozzle drop outs, not clogs per say. These machines don't differentiate between a "clog" and no ink in the nozzle, it's reported as a "clog" so you will know to run a cleaning cycle (either pairs or full).A cleaning cycle does two things ,recharges the head with ink and wipes the outer nozzles to clear away any  (possible) gunk from the exterior of nozzles plate. It's best to always do a nozzle check after a switch, and then do a pairs clean on the offending pairs rather than a full cleaning. If you print that much don't worry about the few$ worth of ink that might be drained to get the nozzle check good again. You should be factoring those costs into to price you charge for prints! You can also print a gradient of the problem colors after a cleaning which helps to draw fresh ink to the nozzles. I have never had the need to do anything but a standard pair clean or sometimes two and a test print, to get the nozzles back!   Set your machine to do auto checks and cleans periodically! When it is set in that mode it will self detect and automatically do necessary cleanings, even if the carts would ordinarily be too low to do a cleaning manually which the machine usually 'requests' a new cart be put in to complete. Any time you get message that says new carts need to be put in and you have more than 2 or three indicators blinking, go out of that indicator mode by stopping the job, and first check exactly which nozzles are "clogged" and only change the necessary carts to do pair cleans.
Example- if the message says you need to do a clean but there is not enough ink in the cart(s) to do it, and you see 4 colors flashing , don't automatically change all 4. Do a nozzle check and see which color(s) is (are) actually bad, and only change that cart or as many as needed, and then proceed with a pair clean.
David  

[iladi]

the biggest weakness of this printer is that ink paths are very very narrow. how on earth someone could think at a such a complicated ink flow, where is a chance of something going wrong at every inch, is beyond my imagination

everything in this printer is extremely complicated and over engineered. I have used Mutoh, Roland, Canon and even older generation Epson printers, but this is the biggest pile of sensors, tubes, cogwheels, more sensors and more wheels I have ever seen. To service the printer is a nightmare. Yes it is a beautiful machine, very easy to operate but it is also very prone to get broken. A murphy's law by itself

[John Caldwell]

My comment, which hardly qualifies as news, is that many of the nozzle drop outs I see on our 4900 and 9900 seem much more to do with air entrainment than clogs. The fact that drops out move around between cleanings and prints, and occur with (or without) ink swaps, is a hallmark of the idea that ink isn't getting to the nozzle - not that the ink can't pass through the nozzle. The fact that a head "cleaning" solves some of the drop outs used to cement the thought that a clog was at fault, but I no longer see it that way.

I'm really looking forward to a better machine from Epson. Some weeks I spend a simply huge amount of time getting clear prints without missing nozzles. I swear that some weeks I spend 3 to 4 times the effort and time in "diagnosis and treatment" vs. the time actually printing. This is just stupid.

John Caldwell

[sunsetcoast]

I said to heck with Epson, it's too much of a pain.  Canon is a solid, extremely easy to use printer and the results are beautiful.  I love the accounting software so I can track all of my ink consumption and media costs per square foot so I know my money is going into media and not wasted ink on cleanings. 

[TylerB]

Not sure this will help, but this is my experience... general nozzle performance problems after K ink swap...

First of all I never let the printer tell me there is a clog or whatever.. I turn all that off and do manual, non-auto, nozzle checks... but-

I was told by someone with more 9900 experience than I, to let the printer sit 20 - 30 minutes after a K ink swap, perhaps this allows the pressure to fully stabalize. Then, just print something. THEN do a nozzle check and see if any cleanings are necessary. If the nozzle check looks too bad, I shut it down, wait a bit, and power back up to make it pressure up from scratch. Again, I always print something like a profile chart before looking at nozzle checks.

Maybe it's all BS, but it helped in my case.

[davidh202]

Not sure this will help, but this is my experience... general nozzle performance problems after K ink swap...

First of all I never let the printer tell me there is a clog or whatever.. I turn all that off and do manual, non-auto, nozzle checks... but-

I was told by someone with more 9900 experience than I, to let the printer sit 20 - 30 minutes after a K ink swap, perhaps this allows the pressure to fully stabalize. Then, just print something. THEN do a nozzle check and see if any cleanings are necessary. If the nozzle check looks too bad, I shut it down, wait a bit, and power back up to make it pressure up from scratch. Again, I always print something like a profile chart before looking at nozzle checks.

Maybe it's all BS, but it helped in my case.

Very sound advice Tyler, not BS at all !
I do the same if needed.
I did say in my post above, that the issue is  a combination of an ink back flow issue, and possible low pressure  , and to print a gradient along with a pair clean or 2. Turning the machine on and off re pressurizes the lines, and charges the head. I use Qimage Ult for my printing, and  it includes a very nice setting in the program to run nozzle print exercises to do just that!

[Garnick]

Very sound advice Tyler, not BS at all !
I do the same if needed.
I did say in my post above, that the issue is  a combination of an ink back flow issue, and possible low pressure  , and to print a gradient along with a pair clean or 2. Turning the machine on and off re pressurizes the lines, and charges the head. I use Qimage Ult for my printing, and  it includes a very nice setting in the program to run nozzle print exercises to do just that!

Hi David,

Although you and I disagree on the use of "Maintenance Mode" for any reason, we do find common ground on some issues involving the Epson printer experience.  And of course a smattering of disagreement is what makes the world go round, right.  Well, the Epson world at least.  I always enjoy a post from Tyler, someone I am familiar with from the "EpsonWideFormat" forum over on Yahoo.  Although I've been spending most of my time here for the past few years, I still visit that forum on occasion to see what's new.  Something Tyler mentioned perked my interest.  The reference to letting the printer sit for a period of time following a K switch.  I immediately put 2 and 2 together and quickly arrived at 5 as usual.  Generally when I do the K switch I'm in somewhat of a rush to get some jobs underway.  Now this next statement is not for your eyes David ; ~)  Since I do my K switch in Maintenance Mode I usually run a nozzle check and do cleanings as necessary while in M Mode.  However, there have been a few occasions when I've done the switch and then on to another job, letting the printer sit before running a nozzle check.  Although I seldom have have nozzle issues after a K switch, I have noticed that when I let the printer sit for a while those issues are almost never present.  It wasn't until I read Tyler's post this morning that I actually put 2 and 2 together again and reached the magic number.  Hence, I will from this point forward, make sure I have enough time to let the printer rest after a K switch.

And to Tyler -- Great to see you here again and I'm sure your offering was not at all BS in any way.  Actually, I find that on this forum any sort of BS is seldom tolerated, nor should it be.  We all have out own individual methods, procedures and ways of dealing with these issues, and we can all learn from one another at some point.  Thanks for that post Tyler.

Gary   

[Paul2660]

Tyler's info is interesting and something I will try next time.  I am always qued up for the next job so I don't wait.  I quit switching in Service mode (Maintenance) since I was getting the clogs there also.  I have auto cleaning off, always have from day one. 

The idea it's a air issue again to me is a good one as I can't see it being a piece of debris since the printer had been working right before the switching of PK to MK.  In these situations, the CL1 in Service mode cleans it almost 95% the first time, it's just the hassle of having to run it.

What I tended to see when switching in Service mode is I got a clean nozzle check, after the switch, but once I started a print, most often by the 2nd print, one full channel dropped out, most times yellow or LLK.  This happened enough times that I had all the dampers changed under warranty, and it seemed to stop for a while, but after about 3 months, I started to see it, but this time only in the PK or MK, whichever ink had been switched back to.  Same thing, a full or 2/3 full channel dropout.  The only way to clear was 3 CL3's or 1 CL3, and I opted for the later. 

Once I started switching in normal mode, the massive drop outs stopped 100%, I just started to see the issue in my first post, which of course still requires a cleaning of some sort.

Paul

[davidh202]

Dampers are rarely the culprit.
I believe the back suction in the head, which temporarily removes some ink from the nozzles after a K switch causing dropouts, occurs right within the head and from the outside of the nozzles, beyond the dampers and long before any air or ink in the lines have enough time to get from the carts to the dampers. Again it's the weakest part of the pressure chain which affects which lines or channels drop out ;-)

[Wayne Fox]

Dampers are rarely the culprit.
I believe the back suction in the head, which temporarily removes some ink from the nozzles after a K switch causing dropouts, occurs right within the head and from the outside of the nozzles, beyond the dampers and long before any air or ink in the lines have enough time to get from the carts to the dampers. Again it's the weakest part of the pressure chain which affects which lines or channels drop out ;-)

agree. Tyler’s recommendation to let the printer sit and then print a page is sound advice ... one purpose of the dampers is to let the air bleed out of the ink supply lines, and if you let the printer sit air pulled in to the nozzles has a chance to move up towards the escape port in the damper so you don’t have to push the air back out through the nozzle.  I’m rarely pressured to produce a job, so when I want to move to matt paper for a print or two (pretty rare for me), I’ll normally make the switch the night before. Next morning I run a black to medium light grey gradient page, then print a nozzle check.  Normally it’s clean, sometimes I have to do one pairs cleaning. but no guarantees ... once in a while I have to work a little to get things cleared up.

Unfortunately the vast majority of Epson printers are used by production houses are dedicated to one black, so it’s difficult for epson to justify the additional expense of pushing both blacks through a set of nozzles.  Additionally if they did this, then many would have problems because one of the blacks would be little used and thus suffer from nozzle issues. If you print a balance of mk/pk, it works pretty good (that’s what we’ve found with our 11880). But it’s sort of a catch 22 for micro piezo based nozzle technology.

[TylerB]

I certainly understand the pressures of fulfilling client's needs as quickly as possible, and like most of you I had 1 9900 so K ink swaps were part of the deal, in my case ~60/40, mk to pk. However I tried to keep expectations reasonable to keep the printer happy, and have whole days or more for one or the other planned in advance. Like Wayne, when doing so I'd make the swap some time before going home i f possible, print nothing, power down before leaving after it sat a bit. Power up in the morning, sit a bit.. print something like a profile chart.. no nozzle checks or cleaning cycles until the first job is ready.. If I couldn't do it over night I'd do what I described above.
I had some pretty catastrophic events after K ink changes.. this kind of thing seemed to eliminate them. You can't keep clients happy and jobs completed with printer problems.
It took some time and experience to deal with the 9900 after years of other Epsons.. the 9900 being the 1st I'd shut down every night. A tech that nearly lived in my shop for several days explained what happens at startup, as others here have talked about, much more elaborate then the x600s, x800s, and the 9880 I have now for quads.
One other point, the last week I had it, I had hundreds of prints to make.. I moved a humidifier right next to it and kept it more humid than ever, it kept going one print after another for 12 hours a day with less problems than ever. We all know about humidity, but I was surprised at the difference when really keeping it up right at the printer, but temperature moderate, and Seattle is not an arid place, duh.
The 9900 seems to hurt you when you try to rush it...

Hope this helps.. can't really say I miss the beast, but the prints are wonderful

[BobDavid]

After I do an ink switch, I have the printer do a nozzle check. And, predictably the test shows areas where the ink isn't showing up. From what I've read, this is caused by air that gets into the lines rather than a clog. So, I've found the best way to fix this is to print a solid 7" X 7" square. Sometimes this I repeat this step once twice. Most of the time, it works. I understand that cleaning cycles are actually mildly destructive--it causes ink to build up on the wiper and is hard on the print head. The family of X900 and X890 printers have a particularly delicate head.