Thing is i've got the only C75 on the island so no one really knows how to get to it.
I guess might have to find a video online
or if you can post where it is in the manual I can't put my hand on it now. Much appreciated and as usual your assistance is spot on.
The tech will know how. Is not quiet simple but you can assist him. The laser units must be cleaned also inside, not just outside as I supposed you did it.
Already cleaned it but will try again
and the little waste toner dots, we found that some toner had spilled under the deverloper unit of the black developer we cleaned it was good for a while then started happening again