Confidential
9-48
I-24
Uneven Density (Right & Left)
Phenomenon
The optical density is different between the right and left side of the printed image.
Main Causes
(1) The amount of toner in the toner cartridge PU is short.
(2) The retract operation of the toner cartridge PU is not properly done.
(3) The belt of the toner cartridge PU is deformed.
(4) The belt of the transfer unit is deformed.
(5) The transfer roller ASSY PU is not properly installed.
(6) The back cover ASSY PU is deformed.
(7) The back cover ASSY PU is not locked sufficiently
(8) The dustproof glass of laser ASSY PU is stained.
Fig. 9-24
Countermeasures
(1) Replace the toner cartridge PU.
(2) Check the toner retract clutch PU.
(3) Replace the belt cartridge PU.
(4) Confirm the proper installation of the transfer roller ASSY PU.
(5) Replace the transfer roller ASSY PU.
(6) Ensure to lock the back cover ASSY PU.
(7) Replace the back cover ASSY PU.
(8) Clean the laser ASSY PU.
(9) Replace the laser ASSY PU.
Toner cartridge PU
(K, Y, M, C)
Laser ASSY PU
Belt cartridge PU
Transfer unit PU
Transfer belt
Back cover 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 ...