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Confidential
9-46
I-22
White Print
Phenomenon
A blank page (no print at all) is output or a specific color is missing (not printed) as shown in
sample [22] of Fig.9-1.
Main Causes
(1) The laser beam path is shielded by the paper.
(2) The toner cartridge is not sufficiently pressed in.
(3) The bias voltage of the transfer roller is not enough.
(Contact failure of the bias terminal of the HV power supply unit PU.)
Fig. 9-23
Countermeasures
(1) Check any paper or other foreign particles to lie in the laser beam path.
(2) Replace the toner cartridge PU with a new toner cartridge PU.
(3) Check the retract solenoid structure.
(4) Check if the transfer roller ASSY PU is installed properly or not.
(5) Replace the HV power supply unit PU with a new HV power supply unit PU.
Toner cartridge PU
(K, Y, M, C)
Laser ASSY PU
Paper tray PU
Belt cartridge PU
Transfer unit PU
Paper feed roller PU
Transfer roller ASSY PU
Registration roller ASSY PU
Transfer unit cleaner PU
Paper exit roller ASSY PU
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 ...