Brother HL-3450CN Service Manual page 301

CHAPTER 8 TROUBLESHOOTING
Error Code
Concerned Part Fan Motor (Control Cooling)
Confirm the connection of a fan motor connector.
Is DCN18 of IOD1 properly connected with a connector of the fan motor ?
Is DCN1 of IOD1 properly connected with 11CN of MCTL PWB ?
Check the voltage (CTFANON-P)
Is the voltage between DCN18-1 and 2 to be a trailing edge ?
Is the voltage between DCN1-33 and 44 to be a trailing edge ?
Is F0 error cleared ?
F0
YES
NO
NO
YES
Job is complete.
NO
Connect them properly.
Is F0 error cleared ?
NO
YES
Replace the fan motor.
YES
Replace the IOD1 PWB.
NO
Replace the MCTL PWB.
MCTL
11CN 5
PGND
44
CTFANON-P
33
+24V-1
PGND
8-38
YES
Job is complete.
IOD1
10
DCN1 DCN18
Control Fan
CTFANON-P
1
44
CTL
PGND
2
33 FAN
CTFANERR
3
DCN2
17
25