Brother MFC8420 Service Manual page 203

CHAPTER 6 TROUBLESHOOTING
Error
Code
(Hex)
73
74
75
76
78
79
7A
7B
7C
80
81
82
83
84
85
86
87
88
A1
Error factor
Drum unit is not mounted.
Toner empty.
In-casing temperature error.
Heater harness disconnected or broken.
Heater thermistor harness disconnected or
broken.
In-casing temperature sensor harness
disconnected or broken.
Main motor does not synchronize with the
reference clock.
ASIC error on the main PCB.
Engine PCB error.
At the start of recording operation, the
controller detects that paper is smaller than
A4 size in length or width.
Paper width sensor remains ON.
Paper feeding error.
Recording paper jam.
(At the retry of paper pulling-in operation,
the registration sensor is not OFF.)
Recording paper jam.
(The paper width sensor and/or registration
sensor has detected a paper jam.)
No paper cassette loaded.
No 2nd paper cassette loaded.
Main motor stop position error.
Recording paper jam.
(Even after paper pulling-in operation, the
registration sensor is still OFF.)
Scanner unit or ink slot cover opened.
• Toner sensor
• Drum unit
• Toner sensor
• Toner cartridge
• Thermistor ASSY
• Thermistor ASSY
• Halogen lamp
• Thermistor ASSY
• Thermistor ASSY
• Main PCB
• Engine PCB
• Main motor
• Paper width sensor
• Paper size
• Paper width sensor
• Paper pick up roller
• Registration sensor
• Main PCB
• Registration sensor actuator
• If the paper width sensor is
defective, replace the needle tube
& head flat cable ASSY.
• Main PCB
• Main motor
• Registration sensor actuator
• If the paper width sensor is
defective, replace the needle tube
& head flat cable ASSY.
• Main PCB
• Scanner open sensor
• Main PCB
• Scanner unit
6-8
Check: