Brother HL-3450CN Service Manual page 293

CHAPTER 8 TROUBLESHOOTING
Error Code
Concerned Part
Is a belt cartridge properly installed ?
Does a transfer drum rotate lightly ?
Confirm the connection of connector.
Is DCN4 of IOD1 properly connected with a connector of drum HP sensor ?
Check the voltage: +5V-1
Is the voltage +5V between DCN4-1 and 3 ?
Is the voltage +5V between DCN2-1 and 2 ?
Replace a low voltage power supply (LVPS).
NO
Is E3 error cleared ?
E3
Drum HP Sensor
YES
YES
NO
NO
YES
Job is complete.
NO
Re-install or replace the belt cartridge.
NO
Is an encoder plate deformed ?
Is a rotation torque excessive ?
NO
Connect them properly
NO
Is E3 error cleared ?
YES
Replace the drum HP sensor.
YES
Replace the IOD1 PWB.
Is E3 error cleared ?
NO
Replace the MCTL PWB.
8-30
YES
Replace the transfer drum.
NO
Is E3 error cleared ?
YES
YES
Job is complete.
MCTL
IOD1
1LCN
5
Drum Encoder Sensor
(EN)
DCN4
HPSEN-N
7
31
31
Relay connector
+5V-1
DCN1
1
HPSEN-N
DCN2
2
LVPS
SGND
3
ACN1 1
+5V-1
1 1
SGND
2 2
1 1
2 2
3
3