Confidential
9-58
[ 6 ] Troubleshooting of the control panel
L-1
Nothing is displayed on the LCD.
User Check
(1) Verify if the power switch is turned off.
Possible cause
Step
Check
Result
Remedy
Connection
between main
PCB and control
panel PCB
1
Main PCB and
control panel PCB
are properly
connected
No
Fix the connector properly.
Harness between
main PCB and
control panel
PCB
2
Harness is damaged.
Yes
Replace the harness with a normal
part.
Connection
between main
PCB and low-
voltage power
supply PCB
3
Main PCB and low-
voltage power supply
PCB are properly
connected.
No
Fix the connection properly.
Harness between
main PCB and
low-voltage
power supply
PCB LCD
4
Harness is damaged.
Yes
Replace the harness with a normal
part.
LCD
5
Replacement of LCD
solves the problem.
Yes
Replace the LCD with a normal
part.
Control panel
PCB
6 Replacement
of
control panel PCB
solves the problem.
Yes
Replace the control panel PCB
with a normal part.
Low-voltage
power supply
PCB
7
Replacement of low-
voltage power supply
PCB solves the
problem.
Yes
Replace the low-voltage power
supply PCB with a normal part.
Main PCB
8
Replacement of main
PCB solves the
problem.
Yes
Replace the main PCB with a
normal part.
Summary of Contents for MFC-9420CN
Page 1: ...Confidential FACSIMILE EQUIPMENT SERVICE MANUAL MODELS MFC 9420CN ...
Page 16: ...Confidential CHAPTER 1 PARTS NAMES FUNCTIONS ...
Page 22: ...Confidential CHAPTER 2 SPECIFICATIONS ...
Page 33: ...Confidential CHAPTER 3 THEORY OF OPERATION ...
Page 48: ...Confidential 3 1 4 CBV DBV Fig 3 16 Y M C K Fig 3 17 ...
Page 69: ...Confidential 3 3 5 Fig 3 35 ...
Page 73: ...Confidential 3 3 9 3 Interface Circuit Printer side Fig 3 38 ...
Page 82: ...Confidential CHAPTER 4 TRANSFER OF DATA LEFT IN THE MACHINE TO BE SENT FOR REPAIR ...
Page 85: ...Confidential 4 2 Cover page sample End page sample Fig 4 1 ...
Page 86: ...Confidential CHAPTER 5 DISASSEMBLY REASSEMBLY AND LUBRICATION ...
Page 94: ...Confidential 5 5 5 1 1 AC Cord 1 Disconnect AC cord from the machine Fig 5 1 AC cord Machine ...
Page 175: ...Confidential CHAPTER 6 ADJUSTMENTS AND UPDATING OF SETTINGS REQUIRED AFTER PARTS REPLACEMENT ...
Page 203: ...Confidential CHAPTER 7 CLEANING ...
Page 205: ...Confidential CHAPTER 8 MAINTENANCE MODE ...
Page 213: ...8 6 Confidential Fig 8 2 Scanning Compensation Data List a b c d e f g h i j k l m n q ...
Page 224: ...8 17 Confidential Cover page sample End page sample Fig 8 8 ...
Page 255: ...Confidential CHAPTER 9 ERROR INDICATION AND TROUBLESHOOTING ...
Page 279: ...Confidential 9 23 2 Image failure 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ...
Page 280: ...Confidential 9 24 15 a 15 b 16 17 18 19 20 21 22 23 24 25 Fig 9 1 ...
Page 325: ...App 1 5 Confidential 6 Transfer Unit X X X X X X 7 1 2 3 Location SERIAL NO YEAR MONTH DATE ...
Page 398: ...B Power Supply PCB 100V 127V Confidential ...