endless problems with the DJ 9000s... any clues?

[joshie]

We bought our 9000s back in August 08. It had 25 heads replaced!!! Can i get to the Guiness book of records? It is still under warranty and still plauged with the same problem - nozzles dropping out during print. And it does it in a funny way - starts printing ok, then just after a meter or less nozzles start dropping out in a growing block. So it's not random nozzles but blocks of nozzles, growing with each pass.

And the coolest (uncoolest, actually) thing about it is that when you run the nozzle check right afterwards, it's 100% ok most of the time!

No air in tubes, dampers, operating conditions are perfect, wipes and caps cleaned everyday and well-adjusted. Happened with both the 790 and 791 ink. Operating conditions are perfect.

Just had a long onsite visit by an HP technician, very professional, but even he was totally confused.

So... never had problems like that with any Seiko 64s or Oce 6060. I know that two things changed since the 64s - printhead voltages and ink formulation.

PH voltages are now much lower than they used to be, maybe it follows the changed ink formulation? New 791 inks IMHO dry faster and give a better looking print, but that doesn't solve the problems at all.

It's all as if there was air in the printhead itself, but... there is no air in the system, so would it be inside the PH? I think not... I'd increase/decrease the PH voltages by 1 or 2 volts, but i don't want to experiment.

Did you guys had similar problems?
Cheers!

 

[Bill Modzel]

We have three years on ours now and absolutely no serious issues.

Your's still under warrantee. If HP can't fix it, maybe it's time to push for a replacement unit.

 

[joshie]

Thanks Bill,

indeed we're pushing for a replacement. However HP claims that we haven't been doing proper daily maintenance. Well... I gotta admit it wasn't entirely systematic, but was caused due to very bad behaviour of the machine.

Two PHs were replaced at install, two additional ones in 3 weeks since installation, altogether 10 PHs replaced in the first three months. Crazy!

So far i only got an offer of warranty extension, free ink etc, but no replacement. I will keep on pushing.

On this forum i just want to check if anyone had any issues even vaguely similar to mine.

Cheers!
Adam

 

[Typestries]

Same issues here on ours, they popped up about a year ago. Drop outs after a meter or two. Cyan and magenta are the worst. We have put over 8 miles of media through our machine, so I expect some issues.

We did turn our printhead voltages up and that helped. Also new dampers and o-rings, that also helped. Also replaced the caps, that helped. We have tried many changes in the room environment no change. We're way out of warranty period. Ours did not do this at first. It is a little better with the new inks.

Please know you are not alone. HP was not too helpful. They just wanted to sell us a bunch of way overpriced parts we did not need. I'm looking at a 3 meter right now, and I can say that because of that the HP 3meter isnt high on my list. Too bad for them.

 

[joshie]

Thanks Rick!

We also have 2 Seiko 64s and 1 Oce 6060, and together they have over 10 years of activity and more than 100 kilometers printed (60 miles, i guess). With this one we were only able to print about 5 km in almost a year, most of it were bad prints.

Today morning we lost the Cyan head. So p****d off right now. It's so good that it's under warranty, however i shiver to think what happens when it ends.

 

[robr]

robr

same thing with mine going on for 6 mo now help help help !!!!!!!!!
think i am going to buy a roland ex 540 .

 

[joshie]

Well robr,

having huge experience with practically identical machines to the HP 9000s, which is the original Seiko 64s and the Oce CS 6060, i expected the HP machine to work perfectly well. After all only three things changed vs the Seiko:
- SCSI turned to USB
- different head voltages
- different ink (although the 790 was produced by Seiko, and the 791 is produced by HP).

I would probably recommend new Seikos, the 74 and 104, but i have no experience with them, except that I know 64s was great (and still is!).

The 9000s/64s/6060 type of machine is a vinyl killer. If set up well, it will print insane amounts of materials with no hiccups. However, the Roland 540 is more like an off-roader - it can print ugly but fast and beautifully but slow. Whatever you like. You don't get so much choice and flexibility with the 9000s, but you get faster output on vinyl.

I'm having the C and Y ph's replaced this week, which in turn will bump the number of replacements to 27! Yay! We'll see how it goes from there.

If that machine was not under warranty, i'd bump up the printhead voltages by 1 or 2V, to the average level of voltages on Seiko. Another thing i'd do would be to use Seiko ink or get a CISS with Sericol inks which in my experience are flawless, tho i don't know if they produce them for the Konica/Minolta KM512 heads.

 

[robr]

hp 9000

hey joshie can you give me a call or pm me
rob@ freedomdecals.net 815-806-8172
thanks rob.

 

[joshie]

Ha, next morning, another daily mainentance and a strong PH recovery, and no cyan nozzles firing. zip. nada. not even a slightest hint. that's weird.

waiting for the service guy to come... i wonder if you can easily exchange PHs between Seiko and HP?

 

[Mspec]

Joshie,

Pretty unusual to have nozzles dropping during a print, but nozzle test 100% right after killing the job. Could be slow ink delivery to the heads, but usually once solvent nozzles stop firing it takes a purge or recovery to bring them back. I've seen media walking on the takeup create what looks like jet dropout, mostly the jet placement goes bad if the media is walking back and fourth through the print zone. If you look at the edges of your media on the takeup, and they telescope back and fourth, your media was not loaded straight resulting in your problem. Secondly, thats an awful lot of heads to have replaced, I would be wondering about either headstrikes or the printhead capping at the end of the day. Either will drastically reduce the lifespan of piezo heads.

Good luck to you with todays service call.

 

[joshie]

Mspec,

well, indeed, that looks like slow ink delivery. I wonder how i could change it. I know i could up the voltages, but that will just spit out more ink, but ink supply stays the same so the problem would get accelerated.

Media walking/telescoping is indeed possible, however i've yet to see it on such a machine. I've seen it on a bigger one we have, but there you can adjust any parameters of carriage and media feed (like acceleration, speed, deceleration, tension, just anything... highly tunable - gandi's are the best).

If i didn't have any experience with such a printer i might take it easier, but I got three other machines which are essentially identical - Seiko Colorpainter 64s and Oce CS6060. They've only seen 4 head replacements per accumulated 10 yrs of activity.

One more thing that's very interesting is that a Normal PH Recovery, either manual or automatic, more often deteriorates the state of the printheads. I wonder if the capping station works well. There is a procedure to check if it works ok - you need to run Wash Printheads procedure and then hard-switch-off the machine, unscrew the side covers, lower the capping station down, move the carriage to the side and see if all cappings have ink. If not - those caps work improperly and need to be replaced or at least cleaned (ink might have accumulated below). But that wouldn't really explain all problems...

Thx anyway, i'll keep y'all updated.

 

[radar]

Where the issues are consistent on a nozzle drop after 1 meter the possibility on HP9000 and Seiko 64s printers is on various points. Could be head rest cycles and Print Head Temp in media reg is off(HP9000 only). Combination of the inks being introduced, 790 first then 791 and the damper is starving the printhead. (damper screen is clogged with particles) Ink line and subtank need to be drained and flushed of all ink and cleaned with cleaning cartridges. (long term storage solvent cartridges). Introduce new ink at this time. The misnomer is that the 790 ink was engineered by Seiko...this is not true. Seiko now has come out with the LX inks that do work with the HP solvent printers and since issues have clearly been a problem from the beginning with the 791 inks...I would suggest going back to the original OEM of the product and get their inks.
You will get the starvation issues on these printers when any air is introduced through the various connections in the ink delivery system. Each connection has an O ring that when printer was assembled the connections were consistently over tightened hence crushing the o rings and introducing air. This sounds like the most obvious of the problem for dropping a color and seeing a color shift during a printer that sees that shift in a 1 meter distance of printing. Yet the head rest during the print cycle can bandaid this air leak problem.

 

[radar]

Seiko and HP solvent printheads are the same. If in the morning you have no printhead firing a color and did your morning and nite before cleanings and then have no firing of a printhead and it takes you multiple cleanings to get that color back. You have an air leak before the printhead or in the printhead. Look through the fan vents on the front of the carriage with a flashlight at the particular ink supply line to the printhead that is not firing and see if that ink line is filled with ink. If it is not you could have a few issues that will cause this: printhead is old, o rings and damper needs replacing. depends on how far the ink travels back to determine what is and how much is needed to be replaced.