Confidential
9-25
I-1 Background
Phenomenon
Background is smeared due to toner spread as shown in
print sample [1] of Fig.9-1.
Main Causes
(1) Too small charging amount in the development process.
(2) Insufficient contact of the developer roller's bias pole.
(3) Life or failure of the belt cartridge PU.
(4) Failure of the HV power supply unit PU (HVU).
Fig. 9-2
Countermeasures
(1) Replace the toner cartridge PU.
(2) Confirm if the developer bias pole is deformed or not.
(3) Replace the belt cartridge PU.
(4) Replace the HV power supply unit (HVU).
Belt cartridge PU
Toner cartridge PU
(K, Y, M, C)
OPC belt
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 ...