Epson 9600 problematic channel

icecream

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Hi all

My 9600 seems to have intermittent issues with the Light Black channel. It tends to jump around from all nozzles working, to half working, to almost none working. Sometimes cleaning cycles help, but usually they make it worse. For example, I was getting near perfect nozzle test results for a few days and printed a bunch of things, and then the printer ran one of its automated cleaning cycles after which the light gray was largely gone again. I'm now at a point however where I am unable to get any better than ~30% LK functioning nozzles.

Some history:
* I acquired the printer a few years ago. Removed and cleaned the head and cleaned all ink tubes. Replaced dampers.
* It had been functioning quite well up until around 6 months ago when the LK channel started to become difficult.
* Printer hasn't been used much, and has sat idle for months at a time.
* I have been using new old stock genuine ink. Around 10 years out of date. I've added some Photo-Flo which was a recommendation I think I found here for old ink.

Things tried:
* Remove and clean LK damper.
* Push Windex through LK channel of print head in situ.
* Three different LK ink/cartridges.
* Ink charge cycle.
* KK2 cycle.

Things observed:
* Drawing ink through damper doesn't feel any more restricted than other channels.
* Ink usage in LK channel was possibly less than other channels, but this could be for many reasons.
* No air in the lines.
* KK2 cycle seems to give best results. Yesterday it recovered to 100%, but then disappeared again during the next print.

This seems like possibly an ink starvation issue, but it's hard to say. In the field repair guide (pg 15) they suggest also checking the 'Ink Valve' (which I assume is what is referred to as the 'Needle Frame ASSY' in the service manual) which is what I guess I'll try next, although it feels like a long shot. The other possibility is that it's an intermittent electrical issue most probably in the head, although the nature of it doesn't seem electrical to me.

Anyhow, just thought I'd tap into the brains trust for any thoughts or suggestions. Appreciate any help.
 

Ink stained Fingers

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Printer hasn't been used much, and has sat idle for months at a time.
Before you got the printer or after ?

I'm running a similar ago-old 7600 and do a small print about twice a week if I don't print posters, I otherwise slowly loose some nozzles if I wait longer and would have to run some cleaning cycles . I replaced the dampers 2x over a longer time. You did about everything you can do to flush and clean the ink path, but please consider a situation that you have some solidified ink particle close to the nozzles which won't fit through the last step of the ink path - the piezo element, so they cannot move away. When you flush the ink path you always should apply a pull/push cycle to have a chance to pull back anything what may have settled there. But I know it's no guarantee that such action will fix the problems. I had some problems longer time ago with the LM and LC channels and even switched to a RIP software which allowed me to run the printer with the CMYK channels only. But suddenly all problems were gone - I don't know which action cleaned the situation.
 

icecream

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Thanks for the reply.

So the printer had been sitting idle for large chunks of time after I acquired and 'serviced' it.

For the recent in situ cleaning of the LK channel, I did do push/pull cycles, but I didn't really leave the Windex sitting for a long period of time. Actually, now that you mentioned it, I noticed at times that there seemed to be quite substantial resistance on the push cycle, but it's possible that was due to air. But I may as well just rip the head out and give it an overnight bath in fluid, and also pop the manifold off and give it a thorough clean.

Do you know if the needle frame assy operates to close the ink channels when the cartridge lock is up? Or is it simply a coupling? I'm just thinking about how complex these things are and therefore how likely they are to require maintenance. Perhaps I'll have a look at it while the heads out.

Will report back.
 

Ink stained Fingers

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I don't know really which cleaner could dissolve coalgulated pigments the best in the tubing and the printhead ink channels and whether an overnight exposure would do it, it is probably worth a try in the current situation.
I assume that the lever at the cartridge compartment closes the tubes, ink otherwise would run back if you disconnect a tube from a damper, and that would be much air to remove in the tubes.
I only remember that the problems with my printer vanished after a while, and I'm now printing something small regularly since then.
 

icecream

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Ok, just reporting back here.

So I pulled and cleaned the head & dampers. The head I let soak in Windex for a few nights, and also in The Pharmacist's Mix for a few nights. In all, it seemed relatively clean, certainly nothing like when I first cleaned it. All channels ran completely clean after a single night basically. In terms of fluid restriction, the LK channel didn't seem different to the other channels when fluid pressure was applied, and the nozzles all seemed fire cleanly.

Interestingly on running an Init Fill cycle, the LK channel took substantially longer for the ink to reach the head which again makes me suspect there's an issue upstream. However that said, after a few cleaning cycles, all channels seem to be operating reasonably. There's a few missing nozzles here and there, but all channels are around 95%+ working. Also, running cleaning cycles doesn't seem to result in a disappearing LK channel now.

So for now at least we're back in action. Time will tell whether it will last, but I'll report back here if things go off the rails again.

Thanks for the replies.
 

icecream

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So after further usage, it seems that the head clean didn't solve the issue, and the LK is still problematic.

I'll have a look at the needle frame assy next as everything is suggestive of an upstream restriction.
 

icecream

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Okay, so I think the issue is finally resolved. It did appear to be an upstream blockage.

I simply removed the LK cart, replaced it with a cart full of Windex, then popped the LK tube off where it enters the damper and pulled the Windex through with a syringe. I let it sit for a day or two, agitating with the syringe plunger occasionally.

LK channel now seems as robust as the others.
 

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