Tech had black streaks. Replaced the drum unit...came back a couple weeks later.
Tech noticed the waste transport container, the black port appeared full while the others
were clean. Thinking there was something clogged, he replaced the waste transport container
(the one under the drums, not the waste toner box).
Brought it back to the shop and we took it apart.
Found a nice sized toner rock in the middle of the black assembly.

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