CHAPTER IV -6
I-2 Dark
Possible cause Step Check Result Remedy HV.GND
contacts
(Fig.4-5)
Density dial 1 Is the density dial at the center
click position? No Set it to the center
click position or
reasonable position.
Corona failure
(soiled wire) 2 Is the corona wire dirty? Yes Clean the corona wire
by using the wire
cleaner.
Corona failure
(contact failure) 3 Are the corona electrodes
between the printer body and
drum unit dirty?
No Clean both electrodes.
Drum unit failure 4 Is the problem solved when the
drum unit is replaced? Yes Replace the drum unit
with a new one.
H.V. power
supply PCB 5 Are there any disconnected
connectors? No Replace the H.V.
power supply.
Main PCB 6 Are there any disconnected
connectors? No Replace the main
PCB.
Driver PCB 7 Are there any disconnected
connectors? No Replace the driver
PCB.