Brother MFC-8460N Service Manual page 329

Error Code
(Hex)
The temperature of the
76
fuser unit is too high.
The
77
turned off when the error
76 or 78 occurs.
78 The temperature of the
fuser unit does not rise.
7A Main motor does not
synchronize
reference clock.
7B, 7C Not used.
7D Dirt in the corona wire.
Not used.
7E, 7F
80 At the start of FAX
message
controller
paper is smaller than A4
size in width.
81, 82 Not used.
<The solution when Error Code
The heater may be overheating when these kinds of error occur. Therefore, the heater is
programmed to turn off the power for 10 minutes after the switch is on for the safety concern when
the error occurs.
To help the heater work properly, it's necessary to follow the operating procedures as below after
taking measures against the cause of the error.
1. Turn off the switch. Wait until the temperature of the heater lowers enough.
2. Turn on the switch.
3. Either display the maintenance mode then returns to the initial original maintenance mode, or
keep the power on for 10 minutes under inspection.
Symptom
power supply is
with the
printing, the
detects that
76, 77, 78 shown in the machine>
Probable Cause
Thermistor defective
Main PCB defective
Power supply
defective
---
Poor connection in the
harness of the thermistor
Halogen lamp defective
Thermistor defective
Main PCB defective
Power supply
defective
Main PCB defective
Main motor defective
Corona wire is dirty.
Regist sensor actuator
does not move smoothly.
Main PCB defective
9-6
Solution
Replace the fuser unit.
Replace the main PCB.
PCB Replace the power supply
PCB.
---
Reinsert and adjust the
harness of the thermistor.
Replace the fuser unit.
Replace the main PCB.
PCB Replace the power supply
PCB.
Replace the main PCB.
Replace the main motor.
Cleaning the corona wire.
Clean the electrodes of the
main body and drum unit.
(Refer to [4] "Location of
ground contacts"
Chapter.)
Set the regist
actuator into place.
Replace the main PCB.
in this
sensor
Confidential