Brother Facsimile Equipment MFC7420 - Manual (Page 243)

Confidential 9-55
L-2 The control panel does not work.
User Check
(1) No
Possible cause Step Check Result Remedy
Key sticking 1 Any key on control
panel is stuck. Yes Clean up the panel cover, or
remove the burrs from panel
cover and panel keys.
Connection
between main
PCB and control
panel PCB 2 Main PCB and
control panel PCB
are properly
connected. No Fix the connection properly.
Harness between
main PCB and
control panel
PCB 3 Harness is damaged. Yes Replace the harness with a normal
part.
Rubber key 4 Replacement of
rubber key solves the
problem Yes Replace the rubber key with a
normal part.
Control panel
PCB 5 Replacement of
control panel PCB
solves the problem.
Yes Replace the control panel PCB
with a normal part.
Main PCB 6 Replacement of main
PCB solves the
problem. Yes Replace the main PCB with a
normal part.
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 Check Result Remedy
Fault in printer 1 Test page can be
printed using the
method described in
8.4.5 ‘Test Pattern 1’
in Chapter 8.
No Check the symptom of the
problem and refer to an
appropriate section in this
Chapter to solve the problem.
Breakage of main
PCB 2 Printing can be made
using an appropriate
PC, printer cable,
and RS-100M? No Replace the main PCB.