VJ1204 missing black nozzles...

[LT4Hawk9]

3 years old, used a couple times a week or so.

I'm missing 10-12 nozzles, all on the black side. I have cleaned the whizz out of it with the "strong" cleanings, and also soaked the head on the cloth saturated with solution. No love. Same thing. The missing heads will occasionally "move" one space or so between test prints, but that's it. I have had the maintenance station out and cleaned all the hoses out (the nozzle up on top was clogged), and the cap gasket looks good to me.

Are there any other tricks that I should try before thinking the worst? The closest service folks I have found are about a $500 service call away, so I hope I can resolve the issue somehow...and without replacing the head!

Thanks!

 

[FatCat]

Soak a piece of coffee filter with cleaning solution, lay it on top of the capping station and park the head. Re-wet the filter every 20-30 minutes. Run a cleaning after 2-3 cycles of this. Keep doing it as long as you can recover nozzles.

 

[LT4Hawk9]

Thanks, Sean!
I did that for at least 4-5 cycles last week. No change in the print pattern, besides the occasional move one way or the other with the missing nozzles. The other 3 colors are 100% fine.

 

[FatCat]

If you have nothing left to lose you can SATURATE a cleaning swab and CARFULLY dab at the black channels on the head. I recently did this on a new to me 1604 and after many attempts I got back the majority of the black nozzles.

I know it goes against everything that you hear about not touching the head, and I must stress that there must be NOTHING on the bottom of the head like grit/dust/ink particles, etc. Because if there are you can possibly jam a piece of debris up into a nozzle.

Again, I would only do this as a last resort if you've resigned yourself to buying a new head anyway. However, if you're only missing 10-12 nozzles I would think the print quality should be sufficient for most projects - even if you have to resort to running higher resolution or a single pass setting.

 

[LT4Hawk9]

Coming into this as a total newbie...what is the point of the cleaning cartridges? I recall putting them in it when it was new and it evidently drew a bunch of solution out of them...then we put in the ink cartridges. To my knowledge, though...we have never been asked to reinstall the cleaning cartridges for anything. What gives with that? I just put them in it thinking there was a "Holy Crap Cleaning" option on it, and it just says "CMYK not original", and won't let me do anything. Might my solution be depleted in the machine or something? I'm cornfused as to why I was sent 4 cartidges and I haven't needed them but once ever...

 

[FatCat]

The cleaning cartridges are usually only used when you are trying to purge the machine for storage or shipping. However, you can crack them open to get the cleaning solution out which is what you would use to clean your drain lines, capping station and also what you would put on the swab to dab at the head.

 

[LT4Hawk9]

Gotcha. Would there be any benefit to running the solution through it at this point, as if we were to be putting it in long term storage?

 

[bob]

The cleaning cartridges are usually only used when you are trying to purge the machine for storage or shipping. However, you can crack them open to get the cleaning solution out which is what you would use to clean your drain lines, capping station and also what you would put on the swab to dab at the head.

You don't have to break them open. Unnecessary and messy.

Ease on down to your local farm or veterinary supply and pick up a 35cc syringe and a long large bore needle. It should coat you less than $2.00.

File the needle dull so you don't stab anything, including yourself and/or the sack of cleaning solution in the cartridge.

Stick the dull needle in the little port on the end of the cartridge, push in some air, then draw out however much you need into the syringe. 35cc is a lot of cleaning fluid. From there you can push what you need out of the syringe onto or into whatever you want.

 

[FatCat]

There, Bob said it best - a hypo would definitely do the trick. I personally don't use the cleaning carts, I buy cleaning solution in a litre bottle from my ink supplier.

Anyway, no, I don't think you'd find much benefit in running the cleaning carts at this point. There is a chance that it may clear out some of the head, but it seems wasteful and unnecessary to me. Again, I don't really see 10-12 missing black nozzles to be a huge problem for most work. At least not enough to warrant a $2000 head. If you dare to try to swab at the head you may even recover a few nozzles along the way. Figure you don't have much to lose and everything to gain at this point. But again, focus on the black nozzles only.

Good luck.

 

[LT4Hawk9]

It is a few more than 10-12. It bands pretty badly when we do black, gray, and darker colors...

 

[FatCat]

My best guess is that your maintenance station is due for replacement. If you haven't done it since new then I guarantee it is due.

I've discovered that typically when you get missing nozzles on either the black channels or the magenta channels it is due to the head not sitting squarely on the rubber seal and/or the seal is not good anymore. If you get a flashlight, you may be able to see if the rubber gasket is seating properly. If there is any gap that should be your clue.

Also, without a good tight seal your pump may not be pulling strongly enough to suck out the plugs in those nozzles.

 

[LT4Hawk9]

I have not replaced it. Not to question the knowledge of folks who have been doing this a lot longer then I have, but just to try to figure out the reason behind it (to quench my thirst for mechanical knowledge)...what wears out on the maintenance station?

I tore mine out and cleaned all the hoses out earlier today. The hose to the nozzle up on top WAS stopped up, but I got it cleared out. I looked the seal over with a magnifying glass, and it looks great: no nicks, no burrs, no flattened out spots. Do the MS's warp? Why the HECK do they cost $500?

I worked in an industrial wastewater pretreatment plant maintenance for a few years, and worked with parabolic pumps a fair little bit...and besides the hose and shoes inside, they have no wear parts. The hose should last a long long time, and the shoes virtually forever! So the pump is fairly foolproof...the plastic shouldn't warp, so it's foolproof...what is there to go wrong besides the seal? Somewhere I saw just the capping station (seal/sponge/etc) without the whole plastic shebang for about $80-$100, IIRC. Is this an option worth checking into? Seems like an extra $400 for the chunk o' plastic and a pump that shouldn't need replaced is a lot to me...

 

[bob]

...

I worked in an industrial wastewater pretreatment plant maintenance for a few years, and worked with parabolic pumps a fair little bit...

Apparently not long enough to know that they're called 'peristaltic' pumps, not 'parabolic' pumps.

 

[LT4Hawk9]

Hey...I spent hours trying to convince my boss it was a centrifuge we operated, not a centerfuge. Gimme a little credit...lol

 

[FatCat]

Not to sound harsh, but no amount of disbelief or questioning will deny the fact that the maintenance station is a replaceable item. These are very simple machines and the more time you spend with them the easier it is to understand and diagnose problems. Trust me, I've seen my fair share of just about everything on these ValueJets.

I personally believe you can still salvage that head if it is only clogged. However, getting your head clean and then putting it back on to a worn out M.S. will result in the same issue in short time. The M.S. is fairly inexpensive next to a head, and it is a much easier fix that you can do yourself.

If it were me, I would keep soaking the head and if you feel up to it gently rub the black channels a bit with a saturated cleaning swab. One swipe per side of the swab and then pitch it for a new one. Get that M.S. replaced and also replace the dampers while you're at it - I imagine those are original too? It's going to take a little work but in the end will be a whole lot cheaper than having to buy a new head, have a tech come to install it and then tell you that you need a new M.S. and dampers to boot.

Good luck to you.

 

[LT4Hawk9]

I understand...I just like to know the howfor's rather than just tossing parts at something. That's why I said that in the beginning. I will get a MS for it, but I really would like to know what wears out in the thing...to determine if the $100 part would give me the same results as the $500 part will.

 

[henryp]

I understand...I just like to know the howfor's rather than just tossing parts at something. That's why I said that in the beginning. I will get a MS for it, but I really would like to know what wears out in the thing...to determine if the $100 part would give me the same results as the $500 part will.

If you maintenance assembly is OK, (no grinding noise, the wiper moves in and out without hesitation), there is no need to replace it if you don't want to. Just replace the cap top. The maintenance assembly and cap tops need replacing regularly (maintenance assembly once a year, cap top every 6 months) because the ink hardens the rubber seal after sometime making it behave more like plastic. In this condition, the seal between the head and the cap is not very good. Consequently, the ink could dry out on the printhead nozzles, you will also not get a good suction when you do a clean. Same thing applies to the tube in the peristaltic pump within the maintenance assembly. After sometime, it losses its efficiency in pumping because the ink causes the tube to shrink and the tube also changes shape, it flattens out over time. The printer will go to the motions of sucking the ink from the cartridges but very little or no ink is actually passing through the head. Have you ever had cartirdges that had empty ink credit on the chips but still had plenty of ink on them?

 

[LT4Hawk9]

Whats the best place to order the MS from for my printer? Anyone's customer service horrendous and I need to stay away from them, or anything like that?

 

[Compilla]

LT4Hawk9:

Did you get your nozzles back?

 

[LT4Hawk9]

I haven't messed with it. We have a big event coming up next weekend, and I will let thet printer sit until I get back. I have been just making my blacks into 100/100/100/100 CMYK since I started having the problems, and it seems to hide most of the banding. It's getting me by until I get it fixed right.