Epson auto nozzle detect

[super_claret]

During printing a run of 20 prints on my 7900, the cyan head dropped all nozzles, resulting in wasted ink and media.  I had foolishly left the room while printing and came back to 4 prints being ruined.

I have the auto nozzle detection switched off at the advice of my supplier, who told me that it just wastes ink on unnecessary cleanings.  I have read that with it switched on, the printer will run a clean if it detects clogged nozzles, even halfway through a print...it will then continue where it left off and complete the print perfectly.  Can any other users advise whether this is true?

Many thanks in advance

[Nora_nor]

Don´t know, but I had two prints ruined when auto nozzle check turned off. I would leave it on.

[Mark D Segal]

I use a 4900 which is essentially the same technology for the printhead (but there could be other significant differences in other relevant components). I leave auto everything turned OFF because when it was all first on it did a lot of work that I considered pretty useless. I have experienced clogs when the printer has not been used for weeks, or the humidity is too dry, but I detect those at the start of each session doing a manual nozzle check and manual cleaning as indicated. I have never, ever experienced a clog developing DURING the time a sheet is in the machine being printed, or indeed hardly ever a change in conditions from one sheet to the next in the same session. But that's just my experience on a related but slightly different printer. As an owner of one of these machines, you are entitled to telephone Epson Pro-Graphics and have a discussion with them about the relative merits of these options. They can be very informative and helpful. Have you done that yet?

[Paul2660]

What you are seeing is different than a normal clog, and in fact I don't believe is a clog.  The issue of 9900 class printers dropping an entire channel during a print run is common.  Mine does it, especially after a PK to MK or MK to PK switch.  No clog I know of can cause a total stoppage of just one channel cleanly.  This is unfortunately something in the electronics, or pressure supply.  There is no way this could be a "clog" as the printer was working perfectly before it drops the entire channel.  Traditional clogs show up as deflections or a missing series of lines from the nozzle check, not the entire pattern.   If you have some time do a Google search on this issue, you will find a lot of well written blogs and web articles describing this dropping of an entire channel behavior on the 9900 family.

I recently was forced to have a head change, and during the change, Epson also replaced the dampers.  Since the change, I have not seen this problem, (last 6 months).  Usage for me is the same.  I strongly believe this 100% channel drop is due to a pressure drop or simple electronic fluke where something in the head or ink delivery system has a momentary failure.  In the past, the only way I can get the channel back, is to run a CL2 level cleaning from the Service mode menu.  I realize this is a cleaning, however this level of cleaning does release and re pressurize the dampers.  Basically resetting the in delivery system. 

Back to your question, I don't think that the auto detect will help.  You sadly have to watch the printer and see if all of a sudden one of the prints looks off, i.e. you no longer are using one of the ink's.  In my case it was orange 55% of the time and Yellow and Light black the rest.  The Light black issue when it happened was hardest to see in the prints. 

In a large job series, I just make it point of stopping and running a nozzle check to see that all the channels are firing.   Since the work was done on my machine, I have not had this issue, but it's way too much of a cost for me to see a 36 x 72 canvas come out missing a channel.

Paul

[Mark D Segal]

Paul, on further reflection I think you are most likely correct - likely a problem other than a clog. That said, I have experienced on my 4900 the total absence of one or more channels after a period of inactivity, and I have been able to always resolve it with successive levels of cleaning-printing, why I suggested what I did; but you're right, the hang-up could well lie elsewhere. I also notice on my 4900 that Cyan is the most susceptible channel for such issues - perhaps there is a story in this.

[Wayne Fox]

A fully dropped channel is usually an issue with the dampers.  If it happens frequently, they probably need replaced.  I think faulty dampers was more of a problem than actual clogging in the 4900 when it was introduced (my 4900 dropped full channels frequently until they were replaced, didn’t do it again).

Regarding using ANC, most do not like to use it because it seems to trigger unnecessary cleans, detecting missing nozzles that don’t actually show up when a nozzle check pattern is printed, as well as cleaning more channels than necessary (like cleaning all channels when you have an issue with 2 colors that do not share a channel, instead of cleaning those 2 channels/4 colors). 

However, when printing a large print run and wanting to do so unattended, we always enable the printer to check the nozzles between each print ... it may trigger a clean when it doesn’t need to, but certainly that’s better than ending up with a bunch of very expensive paper headed to the trash.

[John Caldwell]

I'm with Wayne. I leave Auto Check ON anytime I can't shepherd each any every print through its entirety. For large prints on the 9900, it's always ON because, by definition, I can't react to a nozzle dropout (clog or otherwise) the develops during a big print - whether I detect the dropout or not.

No question the ANC wastes ink needlessly, but ANC does recognize dropouts, irrespective of cause it seems, and it does force ink well enough to "reopen" the nozzle most times. But throwing away a four foot print when banding developed in the last foot of that print irritates beyond.

Will be great when this problem goes away.

John Caldwell

[Mark D Segal]

Will be great when this problem goes away.

John Caldwell

Of course that will probably depend on the engineering of the next generation up from the x900 series. I'm waiting with baited breath, as it's been a while. :-) Thing is, the quality from these machines is so darn good, one puts up with a lot of "stuff" from them, always hoping the next round of models will "fix everything" without sacrificing on the output.