Problem with Epson ET-7750

[Miguel924]

Hi everybody.
I'm a new member from Spain and user of the ET-7750 model.
I hope somebody can help me with a problem I'm experiencing using this printer. The problem is with the black color. When I print forms with black solid color, the headprint leaves very small drops of black ink outside the printing zone, as you can see in the attached photo.

First thing I want say is that I'm using third party inks (but please continue reading) since I bought this printer 18 months ago and this problem started 2 months ago.
The printer is right now at the official Epson repair shop and they have replaced the Printhead. They replaced the black ink with genuine black ink from Epson as well, and the problem persists.
Now they say it may be a problem with the main board. The printer starts to print black color correctly and finishes as in the attached photo what make me suspect that the main board is Ok.
What can be the problem?

Thank you.

 

[Ink stained Fingers]

I'm a kind of irritated that Epson replaced the printhead and you get the printer back causing the same print problems as before .

There is a possible cause for this problem you quite easily can check for, there is a particular weakness with the cleaning unit causing some funny and similar effects.

Please do a first check - the driver somewhere in the extended settings should have an option for 'Thick paper' as I remember it - please do the same test print with the 'thick paper' setting. You might see a difference that the spurious black spots are less or gone.

The problem area is described already in this thread

https://www.printerknowledge.com/threads/et-7750-ink-pool-at-hub-causing-ink-smearing.14082/page-2

The printhead in the idle position is resting on the cleaning unit, you can see some piece of foam there once the printhead moves away, and there is a small gap at the left side of the cleaning unit where a rubber lip is located and removing ink from the nozzle plate. It now happens in the ET7750 printers that you get a pigment ink smear build up
in this area contaminating the nozzle plate from underneath , and the cleaning unit is not able to remove that stuff as it is doing it with the dye inks.

Another test could be if driver settings - paper selection and quality level - make a difference with the occurance of the spurious black spots.

Is it correct that you run with the original Epson pigment black 105 at this time ?

 

[Miguel924]

Hello Ink Stained Fingers.
Thank you very much for taking your time with the reply. In fact, I've been reading this forum for the las week and I read many of your replies to other users. This is what I tried so far:
I tried cleaning the resting foam and surroundigns. No change.
I tried changing the "thick paper", "type of paper" and "print quality" settings. No change.
As I said I was printing with third party ink (all 5 inks), but the Epson official workshop refilled with Epson ink, with no difference.
I'm not an expert, but I was quite confident that this problem would be caused by either the third party ink or a damaged printhead and it seems the technician was as well. But the problem is neither the ink nor the printhead.
I print a lot with this printer (about 15 A3 in photo quality per day). So I have already printed about 5000 of this printings.
Do you think the mainboard may be damaged in any way for using non-original ink?

 

[Ink stained Fingers]

Thanks for feedback, we don't know yet which black ink is causing the problem, just print a smaller black box onto a smaller piece of paper e.g. 10x15 cm - what do you get if you select 'normal paper' with the black and white mode, with the velvet paper selection or a glossy paper selection . This should show as well where the spurious drops are located - leading or trailing after the black box - or even below ?
I'm not sure whether that would be an ink problem - 3rd party or OEM , but please be aware that none of the 3rd party inks are as UV stable as the Epson inks , the stability against UV and ozone is typically pretty poor to very poor.

 

[Miguel924]

I can't do that test now because the printer is in the Epson workshop.
Do you know what ink the printer uses if I choose "photo glossy paper" and "high quality"? Only photo black? Or both blacks?
What if I choose "normal paper" and "black and white"? Will it use the pigment black only?

 

[Ink stained Fingers]

Yes, that's the idea to separate the blacks and to see which ink is causing the effect.

 

[Ink stained Fingers]

I can't do that test now because the printer is in the Epson workshop.

O.k., let us know then what the problem was when you get the printer back.

 

[jurenhobren]

I can't do that test now because the printer is in the Epson workshop.
Do you know what ink the printer uses if I choose "photo glossy paper" and "high quality"? Only photo black? Or both blacks?
What if I choose "normal paper" and "black and white"? Will it use the pigment black only?

Yes, it uses both black! However, I'm currently also facing same issues with Epson 1430! Looking forward for appropriate information to get it resolved!

 

[Ink stained Fingers]

@jurenhobren, the 1430 does not use pigment and dye black inks, it may be better that you start a separate thread showing your problems - e.g. with a sample print , a nozzle check or similar