Brother HL-3450CN Service Manual page 304

Error Code
Concerned Part High-voltage power supply unit (HVU)
Confirm the status of a charger unit.
Is the charger unit properly installed ?
YES
Is a corona wire cut or shorted ?
NO
Confirm the connection of high voltage wiring.
Is there any contract failure of the high voltage (CHV) output terminal ?
NO
Is there any contract failure or short of CHV socket part ?
NO
Replace the high voltage (HVU)
Is F5 error cleared ?
YES
Job is complete.
F5
NO
YES
YES
YES
NO
Re-install the charger unit.
Replace the charger unit or belt cartridge.
Is F5 error cleared ?
NO
Have the electric pole properly contact.
Clean the socket part.
Is F5 error cleared ?
NO
Replace the IOD1 or MCTL PWB.
MCTL IOD1
DCN17
11CN 5
CHV ON
10 10
8-41
HL-3450CN SERVICE MANUAL
YES
Job is complete.
YES
Job is complete.
HVU
2
BCN1
CHV
+24V-1
Charger Unit
1 1
HV
CHV ON-N
7 7
CHVERR
8 8