Brother MFC-9420CN Service Manual

Confidential
9-39
I-15 White Spot / Black Spot
Phenomenon
White spots and black spots appear on the print as shown in print sample [15] of Fig.9-1.
Main Causes
(1) Foreign particles adhere to the OPC belt or the transfer belt.
(2) The OPC belt or the transfer belt is damaged.
(3) Foreign particles mixed in the toner.
(4) Foreign particles adhering to the transfer roller PU, or local deformation of transfer roller PU.
Fig. 9-16
Countermeasures
(1) Remove the belt cartridge PU.
1) Lightly wipe off the foreign particles adhering to OPC belt, using cotton cloth.
2) Replace the damaged belt cartridge with a new cartridge.
(2) Open the
back cover ASSY PU, and check the transfer belt surface.
1) With the cotton cloth, lightly wipe off the foreign particles adhering to the transfer belt.
2) Replace the damaged
back cover ASSY PU with a new back cover ASSY PU.
(3) Remove the toner cartridge PU.
1) Replace the toner cartridge PU with a new cartridge PU.
(4) Replace the transfer roller ASSY PU with a new transfer roller ASSY PU.
Belt cartridge PU
OPC belt
Back cover ASSY PU
Transfer belt
Transfer roller PU

Brother MFC-9420CN Specifications

General

Print technology	Laser
Maximum resolution	1200 x 2400 DPI
Economical printing	Yes
Print speed (black, normal quality, A4/US Letter)	31 ppm
Print speed (color, normal quality, A4/US Letter)	8 ppm
Digital sender	No
Number of print cartridges	4
Scanner type	Flatbed scanner
Scanner features	Scan to: e-mail, image, OCR, file
Copier resize	25 - 400 %
Maximum copy resolution	600 x 600 DPI
Maximum number of copies	99 copies
Copy speed (black, normal quality, A4)	31 cpm
Copy speed (color, normal quality, A4)	8 cpm
Faxing	Color faxing
Fax memory	500 pages
Modem speed	33.6 Kbit/s
Fax speed dialing (max numbers)	200
Total input capacity	750 sheets
Maximum input capacity	250 sheets
Auto document feeder (ADF) input capacity	35 sheets
Maximum internal memory	576 MB
Bundled software	ScanSoft PaperPort Presto! PageManager
I/O ports	IEEE-1284 USB 2.0
Dimensions (WxDxH)	483.5 x 514 x 530 mm
Printer management	BRAdmin Professional, MIB-II
Networking features	10Base-T/100Base-TX
All-in-one functions	Fax, Scan
Color all-in-one functions	copy, fax, print, scan
Compatible operating systems	Windows 98(SE)/ Me/ NT WorkStation 4.0/ 2000 Professional/ XP Mac OS 9.1 - 9.2, Mac OS X 10.2.4+
Sustainability certificates	ENERGY STAR
Power consumption (standby)	85 W
Power consumption (PowerSave)	16 W
Power consumption (average operating)	1090 W
Operating temperature (T-T)	10 - 32 °C
Operating relative humidity (H-H)	20 - 80 %
Market positioning	Business