Dirty Background - Ricoh FW780 Service Manual

1.3 DIRTY BACKGROUND

Clean the optics and check the copy image.
No good
Change the light sensor setting to a lighter position using SP# - -6.
No good
Is the bias voltage correct?
Yes No
Adjust the bias voltage.
Is the toner sensor voltage much lower than the threshold between level 0 and 1?
(Check using SP#--32 referring to Page 2-16.)
No Yes
Check the main board and toner supply clutch.
Is the image density of solid areas high?
No Yes
Check the toner sensor.
Make several blank copies. Is the background still dirty?
Yes No
Check the cleaning blade.
Are the grid voltage and the charge corona current correct?
Yes No
Adjust the grid voltage and/or the charge corona current.
Replace the drum.
SM 6-3 A163