User Check- Page 147

CHAPTER 6  TROUBLESHOOTING

6-25

I-2

Dark

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.

➂

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 engine 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.

Engine PCB
failure

6

Are there any disconnected
connectors?

No

Replace the engine
PCB.

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.