Epson 7880 'halftone banding' issue

[Admiral]

Easier to see zoomed out, but there is a clear line where the halftone seems different.  This is in the same couple approximately 1/2" thick lines going down the screens the long way.  Always in the same couple channels on the screens.




A few halftone jobs we have had to go back to using film instead of the CTS because of this.  It's very noticeable in the print on large halftones of the same opacities..

We replaced the CR encoder strip thinking that would fix the issue but it didn't (this is the help we were given, and other than that would need to pay $2k + for a tech to fix it...).

Here is an example of it which is very obvious:



I've never seen it anything like that bad on a real screen though.

Anyone have experience with this type of banding issue on an Epson? What needs to be done to fix it?

[ebscreen]

So is this on a CTS that uses Epson technology or an actual 7880? I'm cornfused.

Either way, never seen anything quite like that, but knowing how Epson's work I'd
be checking the carriage rail and ribbon connections for any obstructions. Encoder
strip was a good suggestion but usually when those are bad the heads jump all over
and the machine throws errors.

[Admiral]

So is this on a CTS that uses Epson technology or an actual 7880? I'm cornfused.

Either way, never seen anything quite like that, but knowing how Epson's work I'd
be checking the carriage rail and ribbon connections for any obstructions. Encoder
strip was a good suggestion but usually when those are bad the heads jump all over
and the machine throws errors.

It's a CTS using Epson tech.

I'll look into the carriage rail and ribbon connections...thanks

[ebscreen]

Oh, forgot the drive belt too. Check for obstructions/messed up teeth and check the tension. Really easy to do.

It would make sense that something has gotten in there as screens generally have more junk
on them than a piece of paper or film. The mechanisms are also much more exposed than on
a regular printer.

Best of luck!