User Check - Page 217

Confidential

9-29

I-2 

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User Check 

(1)  Check the paper used meets the recommended paper specifications. 
(2)  Check the printer’s environment.  High temperature and high humidity 

conditions can increase the amount of background shading. 

(3)  Clean the corona wire with the wire cleaner. 
(4)  Try installing a new toner cartridge or drum unit. 

Possible cause 

Step

Check 

Result

Remedy 

Ground 

contacts 

Corona failure 
(contact 
failure) 

1 

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

Yes  Clean both electrodes. 

(3) 

Drum unit 
failure 

2 

Is the problem solved after 
replacing the drum unit? 

Yes  Replace the drum unit 

with a new one. 

Toner 
cartridge 
failure 

3 

Is the problem solved after 
replacing the toner 
cartridge? 

Yes  Replace the toner 

cartridge with a new 
one. 

High-voltage 
power supply 
PCB failure

4 

Is the connections of the 
connector between the 
high-voltage power supply 
PCB and the main PCB 
secured correctly? 

Yes  Replace the high-

voltage power supply 
PCB. 

Main PCB 
failure

5 

Are there any disconnected 
connectors? 

No 

Replace the main PCB.