Brother HL-4000CN Service Manual page 236

Step
Checking MCU and HVPS PWB for signal
8 Is P/J12-27PIN<=>P/12-17PIN of MCU
and HVPS PWB 0VDC?
Checking harness ASSY DRV2 for
9 continuity
Is J12<=>J42 continuous normally?
Magenta Toner Cartridge Detached FIP
Step
Initial setting
Check the following for evidence of fault.
Cartridge replacing condition
Toner cartridge switch ASSY (M) replacing
1 condition
Toner cartridge switch ASSY (M) actuator
replacing condition
Toner cartridge switch ASSY (M)
connector replacing condition
Checking toner cartridge switch ASSY
Does toner cartridge switch ASSY function
2 normally?
Using diagnostic tool, check by digital
input test.
Checking drive PWB for signal
3
Is P/J51-13PIN<=>P/J51-14PIN 0VDC?
Checking toner cartridge switch ASSY (M)
4 for signal
Is P/J432-2PIN<=>P/J432-1PIN 0VDC?
Checking toner cartridge switch ASSY (M)
for continuity
5 Is P432-2PIN<=>P432-1PIN of toner
cartridge switch ASSY(M) continuous
normally?
Checking harness ASSY TNR for
6 continuity
Is J51<=>J432 continuous normally?
Checking drive PWB for signal
7
Is P/J42-5PIN<=>P/J42-14PIN 0VDC?
Checking MCU and HVPS PWB for signal
8 Is P/J11-26PIN<=>P/11-17PIN of MCU
and HVPS PWB 0VDC?
Checking harness ASSY DRV2 for
9 continuity
Is J12<=>J42 continuous normally?
Check
Check
V-26
Remedy
Yes
Replace MCU and
Go to step [9]
HVPS PWB
Replace
Replace MCU and
harness ASSY
HVPS PWB
DRV2
Remedy
Yes
Replace the parts
Go to step [2]
concerned
Replace MCU and
Go to step [3]
HVPS PWB
Go to step [4]
Go to step [7]
Go to step [6] Go to step [5]
Replace toner
cartridge
Go to step [6]
switch
ASSY (M)
Replace
Go to step [7] harness ASSY
TNR
Replace drive
Go to step [8]
PWB
Replace MCU and
Go to step [9]
HVPS PWB
Replace
Replace MCU and
harness ASSY
HVPS PWB
DRV2
No
No