DR2000 drum renewal

[Zoollanderhu]

Hi everyone!
I need a little help with a DR2000 drum renewal.
I bought a Katun OPC drum cylinder. So I replaced the used drum cylinder with the new one.
Eventhough in the middle of the image it is noisy, and sometimes on the other part of the image. I cleaned the corona wire and the transfer roller, also the "blade" so called brush.
What can be the problem? I guess as it noised the paper, it can not clear the drum ( I took it out after printing and it was dirty little bit) , how can I improve the cleaning? or how can i repaire the brush ?
What was wrong with the renewal?
thank you in advance!

[Hank]

The OPC drum has, on the drive end ,an additional gear used to move the transference roller. The additional gear is unattached and couples the drive gear by way of very fine radial teeths. Make sure the fitting and matching of the unattached gear is perfect against the drive gear of the OPC, wrong OPC or faulty gear can lead to undue noise during printing.
Another source of noise could be the contact inside the OPC. Such contact could be distorted if the OPC Axle is inserted wrong. Remove the axle carefuly and try to check if contacts are OK.
The brush only requires being carefully cleaned with the shop vacuum cleaner. No chemical of any type should be used on the fine bristles as it will impair the electrical operation during printing.
Advise results.