Brother HL-3450CN Service Manual page 290

Error Code
Name of Part Developer Solenoid (PSL MC)
Confirm the connection of Connector.
Is the connection proper between ECN3 of IOD2 and Solenoid (PSL KC) ?
Is the harness of Solenoid (PSL KC) broken ?
YES
Check the voltage at (PSL KC) ON-N.
Does the voltage drop ( +24V ) between ECN3-7and ECN2-6?
NO
Does the voltage jump ( ) between ECN1-6and ECN2-8 ?
NO
Replace current MCTL PWB with a new one.
Is D6 Error cleared ?
YES
Complete
D6
NO
YES
YES
NO
8-27
Connect the harness.
Connect the connector properly.
Is D6 Error cleared ?
NO
Replace the front cover unit with a new unit.
Replace IOD2 PWB with a new one.
Is D6 Error cleared ?
NO
Re-check
IOD2
MCTC
14
ECN1 ECN3
12CN
PSL(MC)ON-P
6
6
ECN2
+24V-1
3
PGND
6
SGND
8
HL-3450CN SERVICE MANUAL
YES
Complete
YES
Complete
19
+24V-1
8
PSL(MC)ON-N PSL MC
7