Xerox phaser 7760 printer with horizontal white lines

[matty]

Anybody have any ideas what would be causing these horizontal white lines appearing on printouts from a Xerox Phaser 7760 machine? (see attached pdf scan).

Tried a different fuser and transfer roller, so can't be these. Black toner is near end of life, but lines appear in different colours.

[adriansto]

Check if the defect appear on the IBT before the image will transfered to paper.
Can be a dirt on all Ros windows

[Exok]

Dirty ROS windows are easy enough to clean on this machine although from your samples it looks more to me like you have a build up on the metering blade inside the developer housings. Remove the developer housings and look at the developer on the mag roller. If you see areas on the roller where it is lacking developer this is due to a build up on the blade that limits the amount of developer that is applied to the roller. You may be able to use something such as a sheet of paper folded over a few times to insert and move back and forth to clean the blade. You can turn the developer by hand to see if it clears up. If the problem returns I'd suggest totally cleaning it out and installing fresh developer.

[rockdude]

I also think it's the developer assembly. Replace developer housing and developer of each color having this line. A good general rule is if it happens on ALL colors it's a fuser, transfer roller, etc.., but if it's unique to one color check the: In order of likely hood: Imaging Unit (Drum) Laser Window Developer Housing and Developer Toner (Toner starvation due to either low or generic toner) Let us know how it turns out