Brother HL-3450CN Service Manual page 309

CHAPTER 8 TROUBLESHOOTING
Error Code
Concerned Part
Confirm the connection of an laser unit connector.
Is the connector LCN3 properly connected ?
Is the connector PDCN properly connected ?
Are the connector LCN1 and LCN properly connected ?
Replace the laser unit.
Is LL error cleared ?
Replace the MCTL PWB. or
DC power supply (LVPS).
LL
Laser Unit
YES
NO
NO
Connect the connector properly.
Is LL error cleared ?
NO
YES
Job is complete.
MCTL
PD
3
LCN
31
20
8-46
YES
LDU
PDCN
Laser Unit
LCN3
5
LCN1
SM