Xerox 8000 Color not uniform

[Ronen]

We are running a Xerox 8000 with about 2.5 million clicks. For the past 2 years we are having a problem that the techs are trying to solve with no luck. The problem is uneven color varying all the way down the printed sheet. On the top part of the sheet the color is different then on the bottom part.
There no solutions that will last more than a few days of moderate work.
Any ideas how to deal with this problem?

 

[LodAssoc]

There is no solution to the problem. It is in the 7002, 8000AP, and the 700 as well. We've been fighting this issue for a year, all to no avail.

 

[Craig]

We are running a Xerox 8000 with about 2.5 million clicks. For the past 2 years we are having a problem that the techs are trying to solve with no luck. The problem is uneven color varying all the way down the printed sheet. On the top part of the sheet the color is different then on the bottom part.
There no solutions that will last more than a few days of moderate work.
Any ideas how to deal with this problem?

Is the problem lead to tail or inboard to outboard? I had inboard/outboard problems the other day the tech came in and between his laptop and my spectrophotometer we had it resolved in about 1 hour.

 

[Ronen]

It's an inboard to outboard problem. The Tec and I using his laser adjustment software and the spectrometer can get the color visually even more or less but this will not last long after a few K prints the problem is back.
Any Ideas?

 

[Josh]

It's the "smile" setting problem.... basically my understanding is that the lasers are in the middle of the sheet, so when imaging the area in the middle they have a shorter distance to travel than when they're imaging the areas at the edges of the sheet. As the lasers get less powerful over the further distance this leads to lighter areas on the inboard/outboard edges.

It seems to affect some machines more than others and if you've got a good engineer they can minimise it, however it's an issue caused by the design of the machines.