Arts cleaning manual

Hello,

These last months, I noticed that when I printed negatives at 2880 dpi
on Transparencuies (Agfa Copyjet or either on 3M), I had a wire-mark aligned on the
movement of the head. At 1440 dpi, it looks like a silkscreen.

I tried twice to align the printer head as described in "Printer Basic
Guide" using the Epson utility without success.

What astonishes me is that the prints on Epson paper are still very
nice, without streak or silkscreen.

Is it the fist sign of ageing?

I use an Epson 1290 (in USA it is named 1280) and Epson inks.

Did anybody have the same problem?

Thanks for the advice.

Alain