WC7655 Black color quality problem

Hi,

I have a problem with the black color in my WC7665 (check attachment).

I already

1. Changed black drum unit
2. Changed charge corotron

The problem is still there, any ideas?

Thanks

 

Only on K? Possibly the 1st BTR. Make sure that is K and not full color black. Log into admin and run test prints on C,M,Y,K. It could be another color giving you that stripe, it looks like the PCR on one of the drums.

 

Yes, its only K, the other colors are fine. Its weird because the stripe turns darker on dark gray, and lighter on light gray

 

1btr is inside the transfer belt right? It has one for each color?

 

Check how the image of test chart looks on the drum. Probably the problem is in the black developer assy.

 

In 8 years I've never replaced a 1st BTR for IQ reasons.
I also find it odd that the stripe turns darker.
If it's a developer issue you might be able to see the defects (less or uneven developer) on the dev roll when you have the K drum out.

 

I also have never had a 1st BTR issue. But I also have never seen a test pattern look like that.

 

Pop open the developer housing, by removing the drum and the plastic cover held on by 2 screws. Do not remove the 2 Phillips head screws holding the metal plate located under the plastic cover.

Rotate the gears in the back counter, clockwise and look for any inconsistencies with the developer. It should be uniform across the roll.