Brother MFC-9420CN Service Manual page 232

[ 2 ] Error codes shown in the "MACHINE ERROR X X" message
Error Code
(Hex)
20 Laser power error
21 Beam defector error.
NVRAM error
22
23 Engine controller hardware
error
24 Process timing clock error.
25 Developing motor error
26 Main motor error.
Scanner motor error
27
Symptom
Connector LCN3 dose
not properly connected
Laser unit defective
Engine controller board
defective
Connector PDCN dose
Laser unit defective
Engine controller board
defective
Main PCB defective
Control error
Engine controller board
defective
Main motor
I/O board
Toner cartridge gear
defective
Developer gear unit
defective
Developer motor
defective
I/O board defective
Engine controller board
defective
Main motor
I/O board
Connector PDCN dose
Laser unit defective
Engine controller board
defective
9 - 5
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Probable Cause
not properly
connected
defective
defective
defective
defective
not properly
connected
Solution
Connect the connector
properly.
Replace the laser unit
Replace the engine
controller board
Connect the connector
properly.
Replace the laser unit
Replace the engine
controller board
Replace the main PCB
Try the Power Switch
Off/On
Replace the engine
controller board
Replace the main motor
Replace the I/O board
Replace the toner
cartridge.
Replace developer gear
unit
Replace the developer
motor
Replace the I/O board.
Replace the engine
controller board.
Replace the main motor
Replace the I/O board
Connect the connector
properly.
Replace the laser unit
Replace the engine
controller board.
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