Brother mfc8440 Service Manual page 243
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Also See for mfc8440:
- User manual (426 pages) ,
- Software user's manual (183 pages) ,
- Quick setup manual (52 pages)
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CHAPTER 6 TROUBLESHOOTING
I-2
Possible cause
Corona failure
(contact failure)
Drum unit failure
Toner cartridge
failure
High-voltage
power supply
PCB failure
Main PCB
failure
Engine PCB
failure
Dark
User Check
(1) Check the paper used meets the recommended paper specifications.
(2) Check the machine'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.
Step
1
Are the charge electrodes
between the machine and the
drum unit dirty?
2
Is the problem solved after
replacing the drum unit?
3
Is the problem solved after
replacing the toner cartridge?
4
Is the connections of the
connector between the high-
voltage power supply PCB and
the engine PCB secured
correctly?
5
Are there any disconnected
connectors?
6
Are there any disconnected
connectors?
Check
Result
6-36
Remedy
Yes
Clean both electrodes.
Yes
Replace the drum unit
with a new one.
Yes
Replace the toner
cartridge with a new
one.
Yes
Replace the high-
voltage power supply
PCB.
No
Replace the main
PCB.
No
Replace the engine
PCB.
Ground
contacts
(3)
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Table of Contents
Troubleshooting
