Brother HL-3450CN Service Manual page 300

Error Code
Erase Lamp (EL)
Concerned Part
Confirm the connection of a erase lamp connector.
Is DCN7 of IOD1 properly connected with a connector of the erase lamp ?
Is DCN1 of IOD1 properly connected with 11CN of MCTL PWB ?
YES
Check the voltage (ELON-N/P)
Is a single voltage between DCN7-11 and DCN2-25 to be a trailing edge ?
NO
Is a single voltage between DCN1-27 and 44 of IOD2 to be a rising edge ?
NO
Is EL error cleared ?
YES
Job is complete.
EL
NO
YES
YES
NO
Connect them properly.
Is EL error cleared ?
NO
Replace the LED PCB.
Replace the IOD1 PWB.
Replace the MCTL PWB.
IOD1
MCTL
11CN DCN1 DCN7
5
PGND
44
44
ELON-P
27
27
DCN2
PGND
25
8-37
HL-3450CN SERVICE MANUAL
YES
Job is complete.
Relay Connector
Erase Lamp
9
+24V-1
10 1
+24V-1
1
ELON-N
11 2
ELON-N EL
2
9