HP LJ 4100 MFP black stripe

[spree]

Hi,
HP LJ 4100 MFP doing a horizontal black stripe on the upper side of the page, when copying.
Interesting is it makes only when copying from glass.
Through ADF no stripe is appearing.
What can be the problem?

[Wild Bill]

clean the Optics first

[theengel]

When you clean the optics, make sure to clean the white area on the underside of the glass.

[spree]

I've forgot to do a scanner calibration, it solved my problem