Epson 7600 printing problem

[Tyler Boley]

may be the encoder strip, it's easily dislodged and is part of proper horizontal image placement. It's also easily put back in place... much less invasive than some of these other possiblities. Worth looking at.
It's up above the head travel area, runs the length of the head travel, thin mylar like strip, suspended in place with little brackets. If knocked out of one or more, you get odd image placement. Or, it may need replacing.

[Paul Cunningham]

Liz there is also a Yahoo group dedicated to large format Epson printers. Many experienced users are there to help each other.

Paul

Attachment 133405

Hi,

I'm new to the forum, although have looked through posts in the past.

I'm wondering if anyone can help me. I've had the Epson 7600 large format printer for a number of years, and have hit a problem I can't seem to fix.

When I run the nozzle check, half of the light black print is missing. This doesn't happen to other colors, just the light black. It's very precise, as if it's just cut off half way. There is also some 'ghosting' on the numbers underneath (scan of problem attached).

When I've had and printing problems before, and also on this occasion, I've cleaned the print head with a damp cloth by 'shimmying' the head across to remove any dried ink. I also syringed water through the colour pad. I've checked there's no debris in the rollers or anywhere else, and run some deep cleaning and standard cleaning cycles. Nothing is working, and I'm at a complete loss.

Does anyone have any experience of this, and know how to fix the problem? I have some orders to get out, but am completely stuck with the print.

Thanks in advance for any replies.

Liz

[The Deer Gunter]

may be the encoder strip, it's easily dislodged and is part of proper horizontal image placement. It's also easily put back in place... much less invasive than some of these other possiblities. Worth looking at.
It's up above the head travel area, runs the length of the head travel, thin mylar like strip, suspended in place with little brackets. If knocked out of one or more, you get odd image placement. Or, it may need replacing.

The encoder strip is indeed another possibility. Next to finding out whether it's still in position or not, also verify if the strip is still clean. Also the sensor running with the printer carriage over the strip could pick up some dust making the reading of the strip unreliable.

[koraks]

Since all the other channels seem to be printing in the right places and only the light black channel is shifted, I suspect an addressing error. My guess is that this could either be a bad connection or a defect in the print head itself. Reconnect the cables connecting the head to the controller board to see if that changes things. It looks like one address wire is giving no signal, so you might have some dirt on a contact if you're lucky. If you're unlucky, it's a faulty connection between the print head electronics and the nozzle plate, which I suppose would require a head replacement to fix.

[Tyler Boley]

you know, I don't think the LK is shifted.. so much as there is a vertical gap in the LM preceding it.. as well as a the end of all the LK also missing vertically. If you look at the other inks, there are vertical irregularities as well. Bottom line, I doubt my idea about the encoder strip is correct. I don't know what this is... but I'd agree with others proposing something electrical rather than mechanical.

[koraks]

The vertical banding in the other colors is weird and doesn't really fit with my hypothesis either, I have to admit. But it does look to me like the LK channel being shifted; the left-most nozzles are dieting when the right half should be and the right half doesn't seem to be firing at all.

[Greg Miller]

FWIW I never trusted those diagonal line nozzle checks. I always used the solid block nozzle checks - much more comprehensive and accurate. My guess is there is a mechanical problem with this printer involving the print head. I would be tempted to run a head alignment, but think a repair is likely in order.

The newer printers, like my 4900, don't even print anything any more to do a nozzle check and head clean. That's a nice feature.

[endlessly1852]

Thank you all so much for your replies. After my last post, I gave it a rest for the day, then restarted the printer and cleaned the head as before and put distilled water on the pad. I ran one cleaning cycle as a last hope, and the prints started to come off fine. I was all ready with numbers to contact an Epson repair/service technician, and was also looking at options for a replacement printer.

So, for now, I'm up and running. No idea what it was, or if it will likely happen again. Think a service is in order to hopefully help.

Thanks again for your replies,

Liz

[largeformatnumpty]

Hi,

My first time here but I just registered and logged in to give my two pence worth.

I have had two 7600's. The first was perfect (running genuine Epson cartridges) which I should never had sold.
The second was (a year later) a replacement for the first one.

This had had non Genuine ink cartridges in it and I had no end of trouble. Random ink cutting out mid print, blocked head, blocked tubes, which lead to blocked head. Ink drying out very quickly if not used or ran every week.

I ended up selling it to get an rent and then eventually buy an upgrade.

Be careful mixing inks (if you have), to save it sitting for any length of time, start it up and run a print test page once a week to save the cleaning cycle. Uses a lot less ink that way.
If the pad becomes dry, put distilled water on it to soften up the dried ink on the print head.

I hope that helps?

[endlessly1852]

Hi All,

Further to my message posted several months ago, I am once again having a problems printing. The last time, it completely resolved itself by cleaning/running checks etc, and I hadn't needed to carry out some of the things kindly mentioned by people replying.

Yesterday I was running prints off, and left the printer. When I came back, the paper being fed out the bottom had hit something whilst feeding out, and was not coming out properly, which meant the paper was slightly jammed and printing over the same areas.

Since then, the pics attached show what's happened. Missing print and ghosting.

I am trying to do what I did before, but as usual, I am in the middle of a load of work so really need to sort the printer! As the paper got stuck whilst feeding out, my thoughs are that the print head is misalligned, or something to do with the belt timing.

Any advice appreciated, as the printed was working perfectly until the jam happened.

I should also add that since this happened, when I run a test print or alignment/nozzle check, the head makes a more noticeable 'scraping' or 'catching' sound as it moves. this also happened last time. There is nothing stuck under the head, but it seems that it's related to the printing problem.





Thanks,

Liz