Brother HL-4000CN Service Manual page 227

009-342 LOW Density Error FIP
Step
Initial setting
Check the following for evidence of fault.
Transfer roll cartridge ASSY replacing
condition
1
ADC sensor ASSY replacing condition
Print head cartridge ASSY replacing
condition
Residual toner
Checking harness ASSY CTD for
connection
2
Is the harness ASSY CTD connected to
the ADC sensor ASSY normally?
Checking harness ASSY CTD for
continuity
3
Is J136<=>J1361 continuous normally?
Checking harness ASSY front 1A for
Continuity
4
Is P1361<=>J13 continuous normally?
Checking transfer roll cartridge ASSY
Check if an error occurs though the
5
transfer roll cartridge ASSY was replaced
with a new one.
Checking print head cartridge ASSY
Check if an error occurs though the print
6
head cartridge ASSY was replaced with a
new one.
Checking ADC sensor ASSY
Check if an error occurs though the ADC
7
sensor ASSY was replaced with a new
one.
010-317 Fuser Detached FIP
Step
Initial setting
1 Check the following for evidence of fault.
Fuser ASSY replacing condition
Checking fuser ASSY
Remove the fuser and measure resistance
value
2
Is P232-A4PIN<=>P232-A5PIN less than
400K ?
Checking harness ASSY FSR2 for
continuity
3
Is J232<=>J138 continuous normally?
Checking harness ASSY front 1A for
4 continuity
Is P138<=>J13 continuous normally?
Check
Check
V-17
Remedy
Yes
Replace the parts
Go to step [2]
concerned
Replace the
Go to step [3] parts
concerned
Replace
Go to step [4]
harness ASSY
CTD
Replace
Go to step [5]
harness ASSY
front 1A
Go to step [6]
Go to step [7]
Replace MCU and
HVPS PWB
Remedy
Yes
Replace the parts
Go to step [2]
concerned
Replace fuser
Go to step [3]
ASSY
Replace
Go to step [4]
harness ASSY
FSR2
Replace
Replace MCU and
harness ASSY
HVPS PWB
front 1A
No
End of work
End of work
End of work
No