User Check - Page 219

Confidential

9-31

I-4 

All black

User Check 

(1)  Clean the corona wire of the drum unit. 
(2)  The drum unit may be damaged.  Install a new drum unit. 

Possible cause 

Step 

Check 

Result 

Remedy 

Ground 

contacts 

1 

Is the corona wire dirty? 

Yes 

Clean the corona wire 
with the wire cleaner. 

(2) 

2 

Is the corona wire broken? 

Yes 

Replace the drum unit. 

Corona failure 

3 

Are the charge electrodes 
between the printer body 
and the drum unit dirty? 

Yes 

Clean both electrodes. 

(3) 

Harness 
connection

4 

Is the laser unit connected 
to the main PCB correctly? 

No 

Connect the harness 
between the laser unit 
and the main PCB 
correctly. 

High-voltage 
power supply 
PCB failure

5 

Is the problem solved after 
replacing the high-voltage 
power supply PCB? 

Yes 

Replace the high-
voltage power supply 
PCB. 

Main PCB 
failure 

6 

Is the problem solved after 
replacing the main PCB? 

Yes 

Replace the main PCB. 

Laser unit 
failure 

7 

Is the problem solved after 
replacing the laser unit? 

Yes 

Replace the laser unit.