Brother HL-2600CN Service Manual page 328

Error Code
Scanner Unit
Concerned Part
Is the connector LCN3 properly connected ?
Replace the scanner unit.
Is L2 error cleared ?
Replace the MCTL PWB 2.
L2
YES
NO
MCTL
LCN
NO
Connect the connector properly.
Is L2 error cleared ?
NO
YES
Job is complete.
PD LDU
20
YES
SCMCLK
1
Scanner Unit
SCMRDY
2
SCMON
3
GND
4
SM
+24V-1
5
LCN3
SM