Banding on parts of my photo prints

[PeterBJ]

Your default plain paper format, Letter will be perfect for the LF/EJ adjustment. Most countries, inclusive Japan use the A4 plain paper format. I guess the author(s) of the service manual didn't think of other paper formats. You don't need to search for A4 papers.

The region setting from service mode determines default paper format, default units of measure and more, for earlier models also if CD printing was allowed. Many North American printers were modified to print CD's and the region set to Europe. A side effect of this was that the default plain paper format was changed to A4 and the unit of measure was changed from inches to cm.

 

[PenguinLust]

The service tool demanded a media type, so I just went w/whatever the default is. What I found is that LF=4 and EJ=4 were the winners. The service tools has 0s in their combo boxes, so I assumed that was the default. When I changed them to 4 and pushed "Set" I found that they returned to 0s once I started the tool again. So I don't know what they were originally and I can only hope that they are both set to 4. Anyone know what the defaults are?
So I performed a test w/plain paper and "High" quality and there doesn't appear to be any banding. Then I tried it with "Fast" quality (which I think means bidirectional) and there was some pretty stark banding. So far, I don't have a lot of reason to believe I will have problems if I spend another glossy paper on testing, but before I do that, I thought I'd ask if I've done everything right and there's nothing else to try, except giving it a full test.

 

[PenguinLust]

Well, I guess I'll never know.
In the end, I decided to go ahead w/the photo printing and see how it goes. The banding was eliminated (yay!) but the pizza roller effect is now visible to the naked eye But you have to be looking really hard to notice, so I think I'm just going to quit while I'm ahead.
Thanks for all your help guys. It took a long time, but I wouldn't have gotten anywhere w/out you!

 

[PeterBJ]

The pizza roller marks are not caused by a printer defect, but by the photo paper and/or the ink. I suggest to try other paper/ink combinations.