On Sat, 25 Jun 2016 09:49:29 -0500, Ralph Phillips wrote:

Measure the distance between the streaks.

Using the downloadable service manual, or the "Print Quality" help page,
you can isolate which element is contributing to these streaks due to
how far apart they are (each of the rotating elements are a different
diameter, so their tell marks are different spacings apart.)

But the streaks are horizontal, while the rollers must (by nature)
be vertical???