bizhub 421 dirty copies

[YouthAttack]

hi i have a couple of questions for everyone. i have a couple of bizhub 421's out in the field that keep getting dirty copies and i vacuum, clean, and run all the adjustments and around 17k copies later, they get dirty copies again. i even went as far as replaced the drum unit on one of em and they still get dirty really quick! has anyone seen this problem? i havent messed with any LD1 LD2 adjustments but im getting desperate :confused:

[BIG PAPA]

When you say "dirty" what exactly are you referring too. Can you attach samples? Have you replaced developer?

[YouthAttack]

they are more streaky than dirty. its like if it needs a new cleaning blade even though i replaced the whole drum assembly. i will be going there today so i will take a picture. i replaced the developer with the drum at the same time and it only lasted 17k copies before the streaks re-appeared

[copytechman]

I saw something like this on a 421 once, it was caused by the little white gear that drives the drum claws back and forth, it just wasn't meshing well and caused the whole cleaning auger system to ultimately back up. I had to put a small spacer in so that it would mesh better to the cleaning gears.
Hope that helps!

Regards!
A.

[Downunder]

Check the setting for the main charge, it is probably around the 60 mark, increase this to about 120. If you are a bit uncomfortable doing this you can go into "process adjustment" and decrease your toner level setting from "0" to -1. Usually this background is more visible on the second side.

[brent]

have you replaced the corona wires? mabee by replacing the drum that may have made it better. but i have to replace especially main charge corona wires. fairly often. if not you will get little black lines. even if you clean em. still replace them. I only mentioned this becuase nobody else mentioned corona wires..

[fixthecopier]

Brent is correct. check the corona.

[YouthAttack]

fixed it. the cleaning blade is spring loaded on those drum assemblys. one of the springs i guess came off so it was only cleaning one side and was streaking the drum on the other side. i dont know why konica made these terrible design drum assemblys. i preffer the bizhub 600 and even the 920's are cake. thanks everyone for your input!