Brother HL-2600CN Service Manual page 308

Error Code
Name of Part Developer Clutch 2 (DCLK)
Confirm the connection of Connector.
Is the connection proper between ECN13 of IOD2 and Clutch (DCLK) ?
Is the harness of Clutch (DCLK) broken ?
Check the voltage at DCLK ON-N.
+24V
Does the voltage drop ( ) between ECN13-3 and ECN2-6?
Does the voltage jump ( ) between ECN1-4 and ECN2-12 ?
Replace current MCTL PWB 2 with a new PWB.
Is D4 Error cleared ?
Complete
D4
YES
YES
NO
YES
NO
NO
YES
NO
Connect the harness.
Connect the connector properly.
Is D4 Error cleared ?
NO
Replace the clutch (DCLK) with a new clutch.
Replace IOD2 PWB 2 with a new IOD2 PWB 2.
Is D4 Error cleared ?
NO
Re-check
MCTL
12CN
DCL(K)ON-P
4
YES
Complete
YES
Complete
IOD2
ECN1 ECN13
Developer Clutch 2 (K)
+24V-1
4
1
DCL(K)ON-P
3
ECN2
+24V-1 3
PGND
6
SGND
8
DCLK