Brother DCP 8040 - B/W Laser - All-in-One Service Manual page 232

L-2 The control panel does not work.
User Check
(1) No
Possible cause Step
Key sticking 1
Connection 2
between main
PCB, relay PCB,
and control
panel PCB
Harness 3
between main
PCB, relay PCB,
and control
panel PCB
Connection of 4
FPC key
FPC key 5
Relay PCB 6
Control panel 7
PCB
Main PCB 8
L-3 Printing from Macintosh applications fails.
User Check
(1) Verify that the printer driver supplied with the printer has been installed in the system folder and
selected in the selector.
(2) Check the port selected in the selector. The selected port has to match the actual port to which
the printer cable is connected.
Possible cause Step
Fault in printer 1
Breakage of 2
main PCB
Check
Any key on control panel is
stuck.
Main PCB, relay PCB, and
control panel PCB are
properly connected.
Harness wire is damaged.
FPC key is properly
connected.
Replacement of FPC key
solves the problem.
Replacement of relay PCB
solves the problem.
Replacement of control panel
PCB solves the problem.
Replacement of main PCB
solves the problem.
Check
Test page can be printed
using the method described in
3.5 'Test Pattern 1' in Chapter
7.
Printing can be made using
an appropriate PC, printer
cable, and RS-100M ?
6-29
MFC-8440/8840D/8840DN, DCP-8040/8045D/8045DN
Result Remedy
Yes Clean up the panel cover, or
remove the burrs from panel
cover and panel keys.
No Fix the connection properly.
Yes Replace the harness with a
normal part.
No Fix the connection properly.
Yes Replace the FPC key with a
normal part.
Yes Replace the relay PCB with a
normal part.
Yes Replace the control panel
PCB with a normal part.
Yes Replace the main PCB with
a normal part.
Result Remedy
No Check the symptom of the
problem and refer to an
appropriate section in this
Chapter to solve the
problem.
No Replace the main PCB.
SERVICE MANUAL