Others Problems - Brother DCP-8085DN Service Manual

13. OTHERS PROBLEMS

■ The machine is not turned on, or the LCD indication does not appear.
Step
Harness
connection
1
failure of LCD
panel PCB
LCD panel PCB
2 failure
LCD panel failure Is the problem solved
3
Low-voltage
4 power supply
failure
Main PCB
5
■ The fan does not work.
(Verify the position of each fan referring to
code 78)" in Chapter
Step
Harness
connection
1
failure of the
appropriate fan
Charge HVPS
PCB failure
2
Low-voltage
3 power supply
failure
Main PCB
4
Cause
Is the harness of the
LCD panel PCB ASSY
connected correctly?
Is the problem solved
after replacing the LCD
panel PCB ASSY?
after replacing the LCD
panel ASSY?
Is the problem solved
after replacing the PS
PCB unit?
Is the problem solved
after replacing the main
PCB ASSY?
7.)
Cause
Is the harness of the
appropriate fan
connected correctly?
Is the problem solved
after replacing the
charge HVPS PCB
ASSY?
Is the problem solved
after replacing the PS
PCB unit?
Is the problem solved
after replacing the main
PCB ASSY?
Check Result
No
Yes
Yes
Yes
Yes
"4.19 Operational Check of Fans (Function
Check Result
No
Yes
Yes
Yes
3-80
Remedy
Reconnect the LCD panel
PCB ASSY harness.
Replace the LCD panel
PCB ASSY.
Replace the LCD panel
ASSY.
Replace the PS PCB unit.
Replace the main PCB
ASSY.
Remedy
Reconnect the harness of
the appropriate fan
correctly.
Replace the charge HVPS
PCB ASSY. Replace the
fuser unit fan (FU) and air
intake fan (AIR).
Replace the PS PCB unit.
Replace the LVPS fan
(PS).
Replace the main PCB
ASSY.
Confidential