Brother MFC-L8850CDW Service Manual

2-121
Confidential
4.8 Troubleshooting for Fuser Unit Problems
4.8.1 Fuser unit failure
4.9 Troubleshooting for Laser Unit Problems
4.9.1 Laser unit failure
Step Cause Remedy
1 Connection failure of the
center thermistor harness
Reconnect the center thermistor harness.
2 Connection failure of the side
thermistor harness
Reconnect the side thermistor harness.
3 Connection failure of the
heater harness
Reconnect the heater harness.
4 Connection failure of the eject
sensor PCB harness
Reconnect the eject sensor PCB harness.
5 Eject sensor PCB failure Replace the eject sensor PCB ASSY.
6 Low-voltage power supply
PCB failure
Replace the low-voltage power supply PCB
unit.
7 Fuser unit failure Replace the fuser unit.
8 Main PCB failure Replace the main PCB ASSY.
Note:
- Turn the power OFF and then ON again. After the machine is left as it is for about 10
minutes, this problem may be resolved.
- If test print is performed in maintenance mode for service personnel, the machine may
recover from the error. However, note that if this operation is performed while the heater
has not cooled down, the fuser unit may melt.
Step Cause Remedy
1 Connection failure of the laser
unit flat cable
Reconnect the laser unit flat cable.
2 Connection failure of the
polygon motor harness
Reconnect the polygon motor harness.
3 Laser unit failure Replace the laser unit.
4 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