Brother HL-4000CN Service Manual page 246

Front Cover FIP
Step
Initial setting
Check the following for evidence of fault.
1 Drive PWB replacing condition
Front cover replacing condition
Interlock SW actuator replacing condition
Checking interlock SW
Does interlock SW function normally?
2
Using interlock SW, check by digital
output test.
Checking drive PWB for signal
3 Close front cover
Is P/J41-35PIN<=>P/J41-22 0VDC?
Full Stack FIP
Step
Initial setting
Check the following for evidence of fault.
1
Full stack sensor replacing condition
actuator replacing condition
Checking full stack sensor
Does full stack sensor function normally?
2
Full stack sensor using diagnostic tool,
check by Digital Input Test.
Checking harness ASSY front 2 for signal
3 Is P/J139-6PIN<=>P/J139-5PIN
+3.3VDC?
Checking harness ASSY front 2 for signal
Is P/J139-4PIN<=>P/J139-5PIN
+3.3VDC?
4
Check
Check
V-36
Remedy
Yes
Replace the parts
Go to step [2]
concerned
Replace MCU and
Go to step [3]
HVPS PWB
Replace MCU and Replace drive
HVPS PWB PWB
Remedy
Yes
Replace the parts
Go to step [2]
concerned
Replace MCU and
Go to step [3]
HVPS PWB
Replace MCU and
Go to step [4]
HVPS PWB
Replace
harness ASSY
Replace full stack front 1A
sensor Replace MCU
and HVPS
PWB
No
No