Epson 7600 no magenta is nozzle check but it prints magenta?

[Shawn]

Hi All,

It's been a while since I visited but this site has been an enormous help in the past for me starting out..thanks to all of you!

This is another issue of Epson and clogs but I came across something different I thought I would share if it can help others. I have searched online and this forum but have not seen this issue..or I missed it.

I'm working on a friends older Epson 7600 with ink issues. No magenta shows in the nozzle check..cleanings have not made a difference. I have cleaned the cap assembly and wiper and used the Windex "fix" to see if it would clear. "Puddling the Cap" etc.No difference.

I also switched out to a brand new ink cart with no change.

However, I decided to isolate the magenta channel and just print it. In a new Photoshop doc  set to CYMK and set M to 100%, all else to 0, and printed out a swatch.  It printed out a bit light but did show magenta...it was just several small lines.  Then I set it to a solid 8.5 x 11 patch and printed several more..they came out solid magenta.

Wondering if this was partly from the light magenta cartridge, not knowing what a full pure magenta out of this machine was supposed to look like, I did an online search for the hex code to the Epson magenta ink. I came across and downloaded the colour swatch and hex values from marruttusa.com and printed those. All were fine with magenta showing. I did several more large patches and all printed out fine.

If these colour swatches are accurate and print only the missing magenta why would it not show in a nozzle check?
I get a full swatch of all colours even the "missing" magenta channel. A new nozzle check reveals no magenta showing all others are fine. I have printed several 8.5 x 11 swatches of full magenta..but it still is not present in the nozzle check! I'm glad it is present in the swatches and hope it stays there! But?

Can a glitch cause the nozzle check to "miss" the magenta channel? Even if ink is present and the head working?
Additionally I printed out a test image page from Datacolor Print#3 Pro as I would to do a profile and see what the colour range was like..all good even magenta. The colour may seem a bit weak, but it was on a cheap glossy photo paper and I used just the canned profile.

Printed one of my fall images on canvas and it seemed to appear fine..compared to the same image off my 9880. So, another nozzle check and no sign of magenta.

Seems like I'm missing something here or overlooking something obvious. Not sure if my method of colour selection, to isolate the magenta channel only and print it alone , is sound thinking or not? Or should just be happy I now have the magenta printing and not worry about its absence in the nozzle check?

Anyone have any ideas why the discrepancy...seems to be plenty of magenta to print but not in a nozzle check.

[hugowolf]

There is no way to get just one ink, unless you have access to a RIP. I would try printing a Granger chart, it will show banding where the magenta should be. You could also look at the supposed magenta print with a loupe, and I think you will see other colors there.

https://luminous-landscape.com/how-to-create-color-test-charts/

[Shawn]

Thanks..

That is what I was wondering..about isolating just one colour to print. Was unsure if it was possible.

Downloaded a granger chart and will print an see what I get.

[Shawn]

Ok I have printed out the Granger Chart.

How do I interpret it best? The left side into the blues is less "purple" , more condensed, then what I see on my monitor, which is calibrated, but not certian how much of the gamut should show in print? I'm thinking this is a reflection of the msiing magenta?

If ther is any other way to ascertain how much if any magenta is working..other then nozzle check I wold love to have another method.

Thanks for the input.

[RHPS]

You could download QuadToneRIP and simply print the ink separation chart. Allthough it's intended for B&W printing the clibration mode does actually print from each (colour) channel separately.