Brother MFC-9420CN Service Manual

i Confidential
PREFACE
This Service Manual is intended for use by service personnel and details the specifications,
construction, theory of operation, and maintenance for the Brother machines noted on the front
cover. It includes information required for troubleshooting and service--disassembly, reassembly,
and lubrication--so that service personnel will be able to understand equipment function, repair the
equipment in a timely manner and order spare parts as necessary.
To perform appropriate maintenance so that the machine is always in the best possible condition
for the customer, service personnel must adequately understand and apply this manual.
HOW THIS MANUAL IS ORGANIZED
This manual is made up of nine chapters and appendices.
CHAPTER 1 PARTS NAMES AND FUNCTIONS
Contains external views and names of components and describes their functions. Information
about the keys on the control panel is included to help you check operation or make adjustments.
CHAPTER 2 SPECIFICATIONS
Lists the specifications of each model, which enables you to make a comparison of different
models.
CHAPTER 3 THEORY OF OPERATION
Gives an overview of the scanning and printing mechanisms as well as the sensors, actuators, and
control electronics. It aids in understanding the basic principles of operation as well as locating
defects for troubleshooting.
CHAPTER 4 TRANSFER OF DATA LEFT IN THE MACHINE TO BE SENT FOR REPAIR
Describes how to transfer data left in the machine to be sent for repair. The service personnel
should instruct end users to follow the transfer procedure given in this chapter if the machine at the
user site cannot print received data due to the printing mechanism defective. End users can
transfer received data to another machine to prevent data loss.
CHAPTER 5 DISASSEMBLY/REASSEMBLY AND LUBRICATION
Details procedures for disassembling and reassembling the machine together with related notes.
The disassembly order flow provided enables you to see at a glance the quickest way to get to
component(s) involved.
At the start of a disassembly job, you check a disassembly order flow that guides you through a
shortcut to the object components.
This chapter also covers screw tightening torques and lubrication points to which the specified
lubricants should be applied during reassembly jobs.
CHAPTER 6 ADJUSTMENTS AND UPDATING OF SETTINGS REQUIRED AFTER PARTS
REPLACEMENT
Details adjustments and updating of settings, which are required if the head/carriage unit, main
PCB and some other parts have been replaced.
CHAPTER 7 CLEANING
Provides cleaning procedures not covered by the User's Manual. Before starting any repair work,
clean the machine as it may solve the problem concerned.

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