Brother MFC-9420CN Service Manual

Confidential
3-37
<Temperature Control and Safety>
The detection of the fusing temperature is performed by the thermistor and transmitted to
the temperature control circuit. The temperature control circuit makes the comparative
control with the basic control temperature signal and ON/OFF control over the triac (FLS)
so that the temperature of the heat roller will be the preset temperature (PS).
The temperature control is made in terms of the both hardware and software, and detects
any error with the following detection meanings. Upon the detection of such error, the
machine stops and the error message is displayed on the operator panel.
H0: If the wire-cut occurred in the temperature sensor thermistor (TH) or the
breakdown such as wire-cut occurred in the circuit, the wire-cut detection
signal (THERR) is outputted. This signal works to turn off the relay (RY-1)
and the triac (FLS) and subsequently stops the machine.
H1: If the surface temperature of the heat roller continues to be higher than the
preset value of abnormal temperature (TA) for more than the specified time,
CPU forces the HON signal and ACOFF signal to turn off according to the
timer control so that the machine stops.
H2: If the surface temperature of the heat roller does not reach to the preset
temperature (TS) in the specified time after power-on, CPU forces the HON
signal and ACOFF signal to turn off according to the timer control so that
the machine stops.
H3: If the surface temperature of the heat roller continues to be lower than the
preset temperature (TS) for more than the specified time, CPU forces the
HON signal and ACOFF signal to turn off according to the timer control so
that the machine stops.
H4: If the surface temperature of the heat roller continues to be higher than the
preset temperature (TS) for more than the specified time, CPU forces the
HON signal and ACOFF signal to turn off according to the timer control so
that the machine stops.
HA: If the temperature of the heat roller becomes abnormal due to the break-
down of the control circuit etc., the temperature detection circuit (CM2)
transmits the ACOFF signal. This signal turns off the relay (RY-1), and
simultaneously makes the CPU stop the machine.

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