There are two white strips across my black prints of my Xerox 7835. I’ve cleaned the scan glass, replaced two of the 4 drum cartridges (black, cyan), replaced second bias transfer roll and belt transfer cleaner. But white horizontal streaks still an issue. I’ve been told by a Xerox engineer that the black development unit needs cleaning for debris or replacing. How can I do that?
It is not a quiet easy job, normally you need a tech. But if you think you can do it: remove the toner cartridges, drum cartridges, IBT belt cleaner, the yellow handle (lever) that block the drum's cover, drum's cover, front cover (6 screws), a metal plate, a little board, waste pipe assembly, release and lift the dispenser pipe, remove the developer plate and finaly the developer housing.