Options for my 7900

InkjetMall Customer Support Piezography Inks & Printing
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1

Hi,

I’m looking for your thoughts and experienced advice on my next steps in dealing with about 4 lines of missing/deflected Green nozzles. Here’s the nozzle check pattern:

(Edit: See the pattern in the following post on this thread; my first attempt to include the jpg here didn’t work)
Note the odd deflection on the left and right of the missing nozzle area.

Some history and key data points:
[ul]
[li] my 7900 is 5 1/2 years old[/li][li] this is the first time ever that I have not been able to easily clear a missing nozzle using CL1 cleaning[/li][li] from January to June this year I had ZERO clogs, not unusual for me in the winter months; I typically have more missing nozzle problems in the summer[/li][li] the printer is maintained at 45-60% humidity, 68-78 degrees F[/li][li] I shake my cartridges every 4-6 weeks; wiper is changed at least yearly and cleaned periodically[/li][li] I print at least once or twice a week[/li][li] flushing box has never appeared to need cleaning[/li][li] I occasionally clean the cap station pads, though they have never looked like they needed it[/li][li] the Ink Selector (containing the five dampers) has never been changed[/li][li] the printer has never required a service visit[/li][/ul]

What I’ve already tried:
[ul]
[li] Initially I was missing only a few nozzles in green; after a few CL1 cleans with still missing nozzles, I had to put in a new cartridge to continue cleaning attempts since I was already down to 1%; the removed 350ml cartridge was dated 2009 (yes I know, that is a long time)[/li][li] After a few more cleanings (CL2, CL3) and also printing a purge block of 100% density green, the missing nozzle area got bigger (see image); the missing nozzles area now does not change with any further cleanings[/li][li] Heaviest clean I’ve done is a single CL4 on the O/G pair; I have not done any Power Cleans or SSCL[/li][li] Head soak using Bounty towel with warm distilled water[/li][li] saturating cap pad for O/G with CLF007 cleaning fluid (from AmericanInket) and parking head overnight[/li][/ul]

I really like this printer. It has worked extremely well for me since I’ve had it, and I don’t relish having to change horses. But I need to be realistic and consider my options carefully, especially concerning cost. I should also mention that I’ve done a lot of “technician work” on equipment similar to these printers and feel comfortable doing any repair work myself. I have the service manual and field repair guide and the necessary tools.

Here are the options I’m considering:

[ul]
[li] Purchase a refillable cartridge for O/G and PiezoFlush, and do INIT.Fill sequences to flush the O/G channel (with 48 Hour rest in between)[/li][li] same as above but PiezoFlush in all channels to possibly prevent problems in other channels from developing[/li][li] Purchase a new Ink Selector and replace[/li][li] Purchase a new Ink Selector and Head and replace[/li][li] Purchase a new 7900 (with extended warranty of course)[/li][li] Purchase a new Canon instead[/li][li] Convert the 7900 to Piezography K7 (which I’ve been wanting to investigate anyway, but the downside is that I do need to print color as well)[/li][/ul]

Based on your experience, the history of my printer, and the nozzle pattern above (which to me indicates a problem in the head itself):

Should I try an SSCL?
Is it worth trying the PiezoFlush, or should I just bite the bullet and replace the InkSelector and head?
Is there any sense in first trying a new Ink Selector without replacing the head?
I read here on the tech forum about a possible “nuclear cleaning” option for a removed head that Dana was investigating. Has this been documented and if so should I try it?
Are there any other options which I should consider?

Thanks in advance,
Dave

2

Not sure why the attachment jpg didn’t work (it looked fine in the preview). Let’s see if this works:

3

Bump…comments anyone?

Thanks,
Dave

4

We have a lot of customers reporting success with PiezoFlush. SO that is our recommendation to load a cartridge and run the INITIAL FILL.

But, because green ink is so barely used by the Epson RGB printer driver - are you actually seeing micro-banding when you print?

5

Hi Jon,
Thanks for your reply. I do see micro-banding in some large print areas that would include green ink but it’s barely noticeable. It is very noticeable in test images with RGB ramps.

Unfortunately a new additional problem has become apparent. I had a few LLK nozzles missing the other day and a CL2 paired cleaning on LLK/Y took care of it, but now I see an interesting micro-banding problem in flat grey areas of test prints. You can clearly see the whitish line in the attached two images from my test image print. It is very odd; this line appears once at the top of the image, about 5/8 inch from the top of the paper, and again there is a single line at the bottom of the paper, about 1 inch from the paper bottom. You probably can’t see it in the images, but when I look under magnification at the rest of the test image I see the micro-banding continue between the line at the top and the line at the bottom, though it is VERY faint. Above and below these lines there does not appear to be any micro-banding.

All my nozzle checks look fine (except the green of course), so I am at a loss about what is causing this in the grey print area. My only guess is that somehow some LLK nozzles are shooting less ink when the page feed starts and stops in the process of printing the page, but I can’t think of why this would be unless there is some low-level ink starvation happening.

Anyway, I guess I’m looking at doing a PiezoFlush (now probably on both green and LLK) to see if I can resolve both my green nozzle issue and the grey micro-banding.

Thanks,
Dave




6

For anyone interested here’s an update on my 7900: I have now replaced the Ink Selector (no change in nozzle status), and I’ve installed PiezoFlush for 72+ hours on Green and LLK (no change). I still have missing/deflected nozzles in those two colors. The block of missing nozzles in Green is even slightly bigger now than in the JPG I posted above in this thread.

So, I am concluding now that I have a failed head.

Dana, Jon,

  1. Any pointers on where/how to obtain a new F191040 head? I know that parts suppliers like Compass Micro can no longer supply heads. I see them available on many Chinese and Indonesian web sites, some as low as $645. and others as high as $2200. I’m doubting those $645. heads are legitimate/original Epson heads. Is calling Epson the only option for obtaining a head?

  2. With 8 out of 10 of my nozzle channels working perfectly (everything except Green and LLK), what options do I have for converting to Piezography? Would I be able to run any of the K7 formulations including the GO as well?

Many thanks,
Dave

7

Hi Dave~

If you’re still experiencing trouble with your GR and LLK channels after replacing the ink selector unit and charging those channels with PiezoFlush, then I agree you’re likely dealing with issues in the print head… which is unfortunately a common problem with these printers.

I would also be hesitant about the $645 heads, as our reputable suppliers have quoted us around $2,000 for replacement 7900/9900 heads (which is just insane).
Yes, you can certainly use your printer with 8 good working channels as a Piezography printer, we’d just have to modify curves for your custom setup. You could print both matte and gloss Piezography by eliminating the GR and LLK channels, and using GO in the OR channel. The only thing I caution you about is the paper sensor on the print head occasionally detects printed area and stops the GO coating (it’s very inconsistent, and seems to happen more with some customer’s printers than others)

Best regards~ Dana

8

Here’s a final update on the status of my 7900: I have installed a new head (sourced from Epson directly), made all the recommended adjustments per the Service Manual/Field Guide, and now have a perfectly functioning 7900 again. So in my case the missing/deflected nozzles were not really clogs but a head failure. With a new Ink Selector in place and now a new head, I hope I’m set for at least another 5 years on this printer.

Dave

9

I’m glad to hear your printer is working well again, and I hope you get several more years of good prints from it!

Best regards and happy printing~ Dana :slight_smile: