9900-Complete Nozzle Dropout

[Garnick]

Hello All,

I know this has been covered, but I'm not sure this particular procedure was suggested as a quick cure.  The 9900 has been doing well lately and I'm pleased with that.  However, yesterday I lost the cyan nozzle completely within about three rather small prints.  As always, I ran a nozzle check before starting my day's printing cycle and everything was fine.  Once I realized what was happening I ran another check and NO cyan at all.  Not a complete surprise, but also not what we ever want to see.  With the past history of this printer I've had many of these situations, but not recently.  My usual procedure was to start running pairs cleaning cycles, and as of the past year a full colour print between cleanings(as per Mark Segal's advice).  Now my approach has been somewhat refined.  Instead of multiple cleanings and prints I simply run a Pairs Power Clean immediately for a full dropout, and that usually brings the whole nozzle back online without any further cleanings.  Yesterday was no exception, the cyan was fully recovered with one Pairs Power Clean cycle.  However, the following nozzle check revealed that there was now a complete dropout of PK nozzle.  Again, a Pairs Power Cleaning and the PK was back in working order.  A couple of minors cleans for the Cyan and Light Mag and everything has been cooking since then.  Now to the crux of this post.  I believe it has been mentioned that a complete nozzle dropout might likely be due to a low/no pressure problem in the cart.  I was very tempted to shut down the printer and restart yesterday so that all of the carts would be fully pressurized, but of course I was in the middle of a rush job and that wasn't an option.  I'm wondering if any of you folks have found that a shutdown and restart of the printer is perhaps the best way of bringing back a full dropout of a nozzle.  My thinking is that this procedure might be better than running a power clean, even though a regular clean cycle might be necessary after restarting the printer.

Gary        

[davidh202]

I think we have been here before Gary  ;-)
My preferred method is definitely shutdown and restart to recharge the carts and a nozzle check(possible repeat) rather than EVER doing a power clean !
 
I have to ask if this happened  after a PK /MK switch?, which is most often how complete channel dropouts happen to me.
My 7900 is now over three years old and the 9890 over two, and have never had to do a single power clean.

David

[Garnick]

Hi David,

Sorry to take so long to get back to you.  It's been a couple of interesting days here, ice storms and no electrical power for more than a day. 

Yes, I think you are quite aware of some of the history of my 9900, as stated when I took possession and into the first two years and more.  Formerly, if there was a total nozzle dropout I would start running cleaning cycles, interspersed with a full colour print.  That would or could normally mean at least 5 cleaning cycles and prints.  If that didn't work I would then shut down the machine and call Epson, which would usually be followed by a service call and more parts changed.  About 6 months ago I started running a power clean for this sort of problem and it would normally take only one to get the complete nozzle back.  I'm definitely not one who likes the idea of a power clean, but I also don't much like the fact that otherwise I'd be out of commission for a few hours, power down and wait.  As a result, I decided that instead of creeping up on it I would take a more aggressive approach which generally works the first time.  I try to keep the RH over 40%, but some days that's simply not possible, other than building some sort of enclosure around the printer.  That's the reason I asked this question David, I'd like to be able to find an approach that would negate the necessity of a power cleaning.  From this point forward I will try the shut down and restart/re-pressurize approach and see if that works.  It does seem plausible and I hope it will prove to be a workable method.

The answer to your question is no, the total dropout did not follow a PK/MK switch.  And as I mentioned, once I had the Cyan nozzle back the next pattern check showed a complete loss of the PK Nozzle.  It was at that point that I started considering the shut down approach, but I had a couple of rush jobs to get through, so the power clean seemed to be my only alternative at that point.

Thanks for the reply David.  I'll be giving it a try next time this happens.

Have a MERRY CHRISTMAS and a HAPPY, HEALTHY AND PROSPEROUS NEW YEAR!¡!*•*•*

Gary     

[davidh202]

Hi Gary,
As I have also mentioned before, besides PK/MK switches, my dropouts  also tend coincide with carts at 1% level indications.
I think the machines struggle to keep pressurized, and supply ink to the head at this very low level. It may be that it is harder for the pump to actually  maintain enough pressure due to the possibility that the seals to some carts start to leak slightly at this level, and the cart with the weakest seal causes depressurization of a channel.  This becomes the broken link in the chain so to speak.  This of course is just an educated guess on my part, but I believe very  logical when you stop and think about it . The reason I feel this way is that I have learned to remove the low carts and replace them, which also clears the dropout after a OFF -ON cycle to re-pressurize the carts. Never repeatedly remove carts to shake them as this definitely destroys the seals and Epson specifically warns this may occur!   Yes, ink is expensive, but that is all relative to having to call for service, or  possibly destroy a head in the process of being too frugal with ink. I also refrain from using the 700ml carts altogether, the few $ difference in savings of ink costs are built into my pricing of prints. Operating expenses  should be covered in product charges ;-)
I keep clear plastic sheets fully draped over the machines when not in use. I have never had the need to humidify my space, and the 9890 is  right next to the entry door to my store, but then our levels here in Virginia tend to never get too low.
I have never had to go into maintenance mode.  I operate the machines in auto detect -auto clean periodic mode and let them do their thing, and never try to outsmart them or bypass recommended operating procedures clearly listed in the users manual.
I sometimes do not print for as much as 10 or 12 days ,I do a manual nozzle check each time I start a print run, run a pairs clean if necessary for a missing nozzle or two and other than that I, almost always good to go, except for the  already mentioned circumstances above.
I do feel genuinely feel sorry for the few that have legitimate problems with their machines, but I also feel that many have brought more problems upon themselves by not operating their machines as prescribed in the manual.

Have a MERRY CHRISTMAS and a HAPPY, HEALTHY AND PROSPEROUS NEW YEAR!¡!*•*•*
 to you as well
David


 

[Wayne Fox]

While low ink may have something to do with your situation, full color dropouts is often an issue with the dampers.  Had a 4900 that kept losing a couple of channels, damper replacements solved the problem.