Weird banding issue with ET-8550

[Ink stained Fingers]

But here is a commercial download at $5. And here is a free parts catalog.

I purchased the manual quite some time ago, and since I didn't need it yet for my ET-8550 it slowly went into a dark corner of a cabient.
The manual refers to the adjustment program which you have to buy separately, I don't have it.

 

[Epatcola]

Where did you find a copy of the service manual?

You can view it here and might be able to download via this site.

 

[Fried Chicken]

You can view it here and might be able to download via this site.

Worked perfectly, thank you! I'll store this away and hopefully never need it!

 

[thebestcpu]

Hi @hifivoice
Sorry, I am late to the game here.
No, what you see is not normal in "normal" mode printing for the banding lines or the text offset issues.
Since you are printing A4 paper and the 8550 could print A4 paper inserted into the printer in portrait mode (short side going in first) or landscape mode (long side going in first), it occurred to me that I should not assume one or the other. I am clarifying if the errant lines were in the direction of the paper movement or the direction of the print head movement. I apologize if that was already stated; I did not see it in the prior posts.

This may be a dumb question, yet are you running the latest firmware for the printer?

If the image with the banding were put in portrait mode, that would indicate a print head-related issue (the print head itself or the wiring and connectors to the printhead. Note that individual nozzle checks are good for finding clogged nozzles. Yet, it is not representative of failures associated with all print modes and simultaneous firing of a higher number of nozzles.

And you should be upset with the comment from Epson support; I would have felt pushed off with such a generic response that does not match the symptoms you are seeing.
Just my opinion of course.
John Wheeler

 

[Epatcola]

All looked fine, with the exception of the horizontal alignment for colour, where the bars didn't align:

Sorry to be a bit late reading about the actual problem.

I don't know why they call that Horizontal. It is calibrating the paper feed. It prints a bar feeds some paper and prints another bar. If it feeds too little the bars overlap and you see a dark line. If it feeds too much there is a gap between the bars and you see a white line.

I would say the problem has to be dirt or damage on the paper feed roller encoder disc. It counts lines on the disc to know how much paper to feed so missing some lines because the disc is dirty or damaged would result in additional paper fed.

I bet if you run that and the black test multiple times the gap will only show on some of them. The dirt or damage on the disc would have to line up with the paper feed between the bars and I guess the spacing between pairs of bars has to be about one turn of the feed roller so the gap will or won't show on all the pairs.

I would stick a bit of white paper behind the encoder wheel and watch it while printing something photo quality so it feeds paper slowly giving you a chance to see a problem on the disc.