Xerox Phaser 6115MFP User Manual page 203

There are toner smudges on the back side of the page (whether or not it has been
duplexed)
Probable Causes
The two fuser separator levers are adjusted for
envelope printing.
The media transfer belt is dirty.
The media path is dirty with toner.
One or more of the toner cartridges are defective.
The imaging unit is defective.
Abnormal areas (white, black, or color) appear in a regular pattern
Probable Causes
The laser lens is dirty.
A toner cartridge may be defective.
The imaging unit is defective.
Phaser® 6115MFP Multifunction Product
11-30
Print-Quality Problems
Solutions
Return both green fuser separator levers to
the plain paper setting.
Clean the media transfer belt. If you think the
transfer belt should be replaced, contact
Technical Support with the error information.
Print several blank sheets and the excess
toner should disappear.
Remove the toner cartridges and check each
for damage.
If one or more is damaged, replace it.
Remove the imaging unit and check for
damage. If it is damaged, replace it.
Solutions
Clean the laser lens.
Remove the toner cartridge with the color
causing the abnormal image. Replace it with a
new toner cartridge.
Remove the imaging unit and check for
damage. If it is damaged, replace it.