User Check - Page 222

Confidential

9-34

I-7 

Black and blurred horizontal stripes 

User Check 

(1)  The drum unit may be damaged.  Install a new drum unit. 
(2)  Check the paper used meets the recommended paper specifications. 
(3)  Clean the printer interior and the corona wire in the drum unit. 

Possible cause 

Step

Check 

Result 

Remedy 

Ground 

contacts 

Scratch on the 
drum 

1 

Are the horizontal stripes 
at 74mm (exposure drum) 
intervals? 

Yes 

The exposure drum was 
scratched.  Replace the 
drum unit. 

Toner stuck 
on the 
developer 
roller 

2 

Are the horizontal stripes 
at 37mm (developer roller) 
intervals? 

Yes 

After printing several 
pages, the problem will 
disappear. 
If not, replace the toner 
cartridge. 

Scratch on the 
heat roller 

3 

Are the horizontal stripes 
at 79mm (heat roller) 
intervals? 

Yes 

Replace the heat roller. 

Corona 
contact failure

4 

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

Yes 

Clean both electrodes. 

(3) 

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. 

I-8 

Black vertical streaks (in a gray background) 

Possible cause 

Step 

Check 

Result

Remedy 

Ground 

contacts 

Translucent 
stain on the 
scanner 
window 

1 

Is there any dirt on the 
scanner window? 

Yes  1)  Clean the scanner 

window.  

2)  If it is not effective, 

replace the laser 
unit. 

Corona failure 

2 

Is the corona wire dirty? 

Yes  Clean the corona wire 

with the wire cleaner. 

(2)