Brother MFC990CW Service Manual page 145

Error Code
Symptom
(Hex)
8A The paper feed motor
does not rotate.
8B The paper feed motor
stops suddenly.
8C Current protection for
the driver IC activated in
paper feeding operation.
8D The paper feed motor
rotates in the reverse
direction.
8E Not used.
Probable Cause
Foreign materials in the
machine
Paper feed motor harness not
connected correctly
Abnormal load applied to the
paper feed roller
PF-related gear(s) broken
PF encoder disk stained or
scratched
PF encoder sensor defective
Paper feed motor defective
Main PCB defective
Abnormal load applied to the
paper feed roller
PF-related gear(s) broken
PF encoder disk stained or
scratched
PF encoder sensor defective
Paper feed motor defective
Main PCB defective
The driving current has
exceeded the limit due to an
abnormal load applied to the
PF-related gears and rollers.
PF encoder disk stained or
scratched
PF encoder disk dislocated
PF encoder sensor defective
Paper feed motor defective
Abnormal load applied to the
paper feed roller
Main PCB defective
4-20
Solution
Remove foreign materials.
Reconnect the paper feed
motor harness.
Replace the PF-related gear(s).
Replace the PF encoder disk.
Replace the PF encoder/
registration sensor harness unit.
Replace the engine unit.
Replace the main PCB.
Replace the PF-related gear(s).
Replace the PF encoder disk.
Replace the PF encoder/
registration sensor harness unit.
Replace the engine unit.
Replace the main PCB.
Replace the PF encoder disk.
Replace the engine unit.
Replace the main PCB.
Replace the PF encoder disk.
Replace the PF encoder/
registration sensor harness unit.
Replace the engine unit.
Check the PF roller gear and its
related gears.
Replace the main PCB.
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