epson 9700 banding, dark/white

[artbhai]

Hi
We have a couple of Epson 9880s printers running well with sublimation inks.
we recently purchased 9700 as it is very fast.
Initially we got dark banding. with adjustment, we could remove that. but now we have thin white lines only on left side of the print.
checked nozzle, fine.
priner is running at 360x720 one direction. if we use bi direction, the white lines are across the print. (not 100% sure of this as did this only a couple of times, can check tomorrow)
in addition there are two deep thin white lines at the start of the print.
As we have used sublimation ink with refillable carts, dont expect epson help.
1. is it a paper feed issue? or head issue? or allignment? what else needs to be checked?

 

[JasonFF]

That's an interesting one isn't it? After pondering this for a while I think the issue must be with the carriage, or the print cartridges / nozzles.

If the lines were only on one side of the print no matter what, I might suspect the feeding was some how skewing the paper. But, if you see the lines only on one side with unidirectional print, but see it on both sides with bidirectional print this probably eliminates a feeding problem.

It may be that certain nozzles in the printhead are being used only on the one side of the print, and that might be the culprit. However, this would typically only be a problem for a given CYMK Cl Ml color - not all colors.

If I had to make a guess I'd say that the carriage or carriage motor was the problem, since those are the only things really affected by bidirectional or unidirectional printing.

As for what else needs to be checked, I would try printing a full color full length print section both uni and bi directional, and then do the same with color seperations. Hopefully that would help you nail down exactly when the problem occurs.

I'd be interested to know what you try next, or how you solve the problem.

 

[artbhai]

yes, i will try with c m y k color patches. running full width.