Brother MFC-L8850CDW Service Manual

2-100
Confidential
■ Dark
■ Poor fixing
< User Check >
- Check the machine’s environment. High temperature and high humidity
or low temperature and low humidity conditions can cause this problem.
- After a new toner cartridge is detected, check if other toner cartridge is
not inserted.
- Execute density adjustment from the control panel.
- Clean the corona wire of all four colors on the drum unit.
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
- Replace the belt unit with a new one.
Step Cause Remedy
1 Dirt on the electrodes of the
main body and the drum unit
Clean the electrodes of the main body and
the drum unit.
(Refer to Fig. 2-7 (P2-55) , Fig. 2-8 (P2-55) .)
2 Dirt on the electrodes of the
main body and the toner
cartridge
Clean the electrodes of the main body and
the toner cartridge.
(Refer to Fig. 2-7 (P2-55), Fig. 2-10 (P2-98).)
3 Dirt on the electrodes of the
main body and the belt unit
Clean the electrodes of the main body and
the belt unit.
(Refer to Fig. 2-7 (P2-55) , Fig. 2-11 (P2-99) .)
4 Dirt on the electrodes of the
high-voltage power supply
PCB
Clean the electrodes of the high-voltage
power supply PCB.
5 Density sensor failure Replace the registration mark sensor unit.
6 Fuser unit failure Replace the fuser unit.
7 High-voltage power supply
PCB failure
Replace the high-voltage power supply PCB
ASSY.
8 Main PCB failure Replace the main PCB ASSY.
9 Laser unit failure Replace the laser unit.
< User Check >
- Check the machine’s environment. High temperature and high humidity
or low temperature and low humidity conditions can cause this problem.
- Clean the corona wire of all four colors on the drum unit.
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
- Replace the belt unit with a new one.
- Wipe the scanner windows of the laser unit with a soft, lint-free cloth.
Step Cause Remedy
1 Dirt on the electrodes of the
main body and the belt unit
Clean the electrodes of the main body and
the belt unit.
(Refer to Fig. 2-7 (P2-55) , Fig. 2-11 (P2-99) .)
2 Fuser unit failure Replace the fuser unit.
3 High-voltage power supply
PCB failure
Replace the high-voltage power supply PCB
ASSY.
4 Low-voltage power supply
PCB failure
Replace the low-voltage power supply PCB
unit.
5 Laser unit failure Replace the laser unit.
6 Main PCB failure Replace the main PCB ASSY.

Brother MFC-L8850CDW Specifications

General

Type	all in one
Color	white
Tray Capacity	300
Automatic Document Feeder Capacity	50 sheets
Paper Size	8.5"x14"
Paper Handling	up to 300 sheets
Color Print Speed	32 pages per minute
Mono Print Speed	32 pages per minute
Print Resolution Color	up to 2400 x 600
Maximum Number of Pages Per Month	unknown
Scanner Type	flatbed
Scan Resolution	up to 2400 x 1200
Copier Resolution Mono	up to 600 x 600
Copier Resolution Color	up to 600 x 600
Cartridges	tn331bk, tn331c, tn331m, tn331y
Number Of Cartridges	4
Internal Memory	yes
Memory Card	no
Network	wired, wireless
Connectivity	usb, google cloud print
OS Compatibility	windows, mac os, linux
Mobile Devices Connection	yes

Weight and Dimensions

Height	19.3 inches
Width	20.7 inches
Net Weight	67.4 pounds