Brother MFC-8370DN Service Manual

3-52
Confidential
■ Completely blank
■ Image distortion
<User Check>
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
Step Cause Check
Result Remedy
1
Developing bias
voltage
conduction
failure
Are the electrodes on
the drum unit and
machine body dirty?
Yes
Clean both electrodes.
(Refer to Fig. 3-2, Fig. 3-3.)
2
Scanner harness
of the laser unit
connection
failure
Is the scanner harness
of the laser unit
connected securely?
No
Reconnect the scanner
harness of the laser unit.
3
Laser unit failure Is the problem solved
after replacing the laser
unit?
Yes
Replace the laser unit.
4
HVPS PCB
failure
Is the problem solved
after replacing the
HVPS PCB ASSY?
Yes
Replace the HVPS PCB
ASSY.
5
Main PCB failure Is the problem solved
after replacing the main
PCB ASSY?
Yes
Replace the main PCB
ASSY.
Step Cause Check
Result Remedy
1
Laser unit not
assembled
correctly
Is the laser unit
assembled into the
machine securely?
(Check if there is no
gap.)
No
Assemble the laser unit
correctly and secure the
screw.
2
Incorrect
radiation angle of
scanner diode of
laser unit.
Scanner motor
rotation failure
Is the problem solved
after replacing the laser
unit?
Yes
Replace the laser unit.
3
Main PCB failure Is the problem solved
after replacing the main
PCB ASSY?
Yes
Replace the main PCB
ASSY.

Brother MFC-8370DN Specifications

General

Duplex printing	Yes
Print technology	Laser
Maximum resolution	1200 x 1200 DPI
Time to first page (black, normal)	8.5 s
Print speed (black, normal quality, A4/US Letter)	28 ppm
Input color depth	48 bit
Optical scanning resolution	600 x 2400 DPI
Copier resize	25 - 400 %
Maximum copy resolution	1200 x 600 DPI
Maximum number of copies	99 copies
N-in-1 copy function (N=)	2, 4, 9, 16, 25
Copy speed (black, normal quality, A4)	28 cpm
Faxing	Mono faxing
Fax memory	500 pages
Modem speed	33.6 Kbit/s
Total input capacity	250 sheets
Total output capacity	150 sheets
Multi-Purpose tray input capacity	50 sheets
Auto document feeder (ADF) input capacity	20 sheets
Display	LCD
Product color	Grey, White
Market positioning	Home & office
Display number of lines	2 lines
Display number of characters	16
Card reader integrated	-
Sound power level (standby)	30 dB
Sound pressure level (printing)	56 dB
Paper tray media types	Bond paper, Envelopes, Labels, Plain paper, Recycled paper, Transparencies
Non-ISO print media sizes	Executive
ISO A-series sizes (A0...A9)	A4, A5, A6
ISO B-series sizes (B0...B9)	B5
Maximum ISO A-series paper size	A4
Multi-Purpose Tray media weight	60 - 163 g/m²
Standard interfaces	Ethernet, USB 2.0
USB 2.0 ports quantity	1
Dimensions (WxDxH)	531 x 451 x 475 mm
All-in-one functions	Copy, Fax, Scan
Color all-in-one functions	Scan
Power consumption (standby)	85 W
Power consumption (average operating)	680 W
Package weight	21100 g
Digital sender	No
Maximum duty cycle	- pages per month

Weight and Dimensions

Depth	443 mm
Width	390 mm
Height	442 mm