After many try.
I don't know why but sometimes there is ink in the captop (after a single cleaning it's ok).
I changed the linear encoder, still have some trouble but it's really weird, because when I print a file from Versaworks, it's ok except all the print Area is black (like the 1st Picture).
So I think it's the head print, but I want to be sure. A bad head print could create linear error ?