Brother MFC-7220 - Page 188

Confidential
9-7
Error Code
(Hex)
Symptom Probable Cause Solution
Thermistor defective Replace the fixing unit.
PS PCB unit defective Replace the PS PCB unit.
6F Hardware on the main PCB
turns off the heater forcibly
since the thermistor detects
that the fixing unit
temperature exceeds the
setting one.
Main PCB defective Replace the main PCB.
70 Not used.
Laser scanner unit ASSY
harness not connected properly.
Reconnect the laser scanner
unit ASSY harness.
Laser scanner unit ASSY
defective
Replace the laser scanner unit
ASSY.
71
Polygon motor of laser
scanner unit ASSY does not
synchronize with the
reference clock.
Main PCB defective Replace the main PCB.
Laser scanner unit ASSY
harness not connected properly.
Reconnect the laser scanner
unit ASSY harness.
Laser scanner unit ASSY
defective
Replace the laser scanner unit
ASSY.
72
Beam detect signal of laser
scanner unit ASSY cannot
be detected.
Main PCB defective Replace the main PCB.
Install the drum unit. The toner sensor is always ON.
Replace the toner sensor PCB
ASSY.
73 Toner cartridge or drum unit
not installed.
Main PCB defective Replace the main PCB.
Toner empty Replace the toner cartridge.
Toner sensor PCB defective Replace the toner sensor PCB
ASSY.
74 Toner sensor detects no
toner in the toner cartridge.
Develop roller counter
reaches the upper limit.
Main PCB defective Replace the main PCB.
Fan broken Replace the fan.
In casing temperature sensor
defective
Replace the in casing
temperature sensor.
75 In casing temperature sensor
detects definite temperature
or higher.
Main PCB defective Replace the main PCB.
Fixing unit thermistor defective
(Short-circuited)
Replace the fixing unit.
PS PCB unit defective Replace the PS PCB unit.
76 Fixing unit temperature goes
up too high.
Main PCB defective Replace the main PCB.
77 Fixing unit temperature goes
up too high. (The machine is
turned off when the error 75,
76 or 78 occurs.)
The error history disappears. Leave the machine for 10
minutes while keeping the
power on.
Fixing unit thermistor harness
not connected properly.
Reconnect the fixing unit
thermistor harness.
Fixing unit thermistor defective
Halogen heater failure
Replace the fixing unit.
PS PCB unit defective Replace the PS PCB unit.
78 Fixing unit temperature does
not go up. Or heater
thermistor harness is
disconnected or broken.
Main PCB defective Replace the main PCB.
In casing temperature sensor not
connected properly.
Reconnect the in casing
temperature sensor.
79 Temperature sensor harness
disconnected or broken.
In casing temperature sensor
defective
Replace the in casing
temperature sensor.