Troubleshooting Image Defects - Brother HL-1020 Service Manual

3.2

Troubleshooting Image Defects

The following procedures should be followed in the event of specific image defects.
See subsection 3.3 for information about the location of the high-voltage contacts and
grounding contacts.
Caution:
Print quality can not be guaranteed in the following cases;


When using the printer for a special job, such as printing of name cards.


When printing much narrower paper than printable paper width.


When printing on one area of the paper continuously even though Letter or A4-size
paper is used.
I-1 Light
Possible cause Step
Toner sensing 1
failure
(printer side)
Toner sensing 2
failure
(toner cartridge
side)
Drum 3
connection
failure
High-voltage 4
power supply
PCB failure
Panel sensor 5
PCB or main
PCB failure
Scanner unit 6
failure
Check
Can printing be started with the
drum unit removed?
Is the problem solved when 4
or 5 pages are printed after the
toner cartridge is replaced with
a full one?
Are all the contacts (HV, GND)
connected when the drum unit
is installed?
Check the harness connection
between the high-voltage
power supply PCB and the
panel sensor PCB.
Perform the same check as
step 4 above and also between
the panel sensor PCB and the
main PCB.
Is the problem solved by
replacing the scanner unit?
IV-5
Result Remedy
Yes Toner sensor failure.
Check if the toner
sensor needs
cleaning and check
the toner sensor
connection.
Yes The wiper of the
toner cartridge is
defective.
Replace the toner
cartridge.
No Clean contact
electrodes both in the
printer body and on
the drum unit.
No If the connection is
normal, replace the
high-voltage power
supply PCB.
No Replace the panel
sensor PCB or the
main PCB.
Yes Replace the scanner
unit.
HV.GND
contacts
(Fig.4-5)