Brother HL-2600CN Service Manual page 303

Chart 8-4 Troubleshooting
Code Description of Error
C3 NVRAM Error
Does the error repeat despite of implementing "On/Off of Power Switch" ?
Does the error repeat despite of implementing "NVRAM INITIAL" ?
Replace the failed MCTL PWB 2 with a new MCTL PWB 2.
Code Description of Error
Hard Error of MCTL
C4
Control Circuit.
Does the error repeat despite of implementing "On/Off of Power Switch" ?
Replace the failed MCTL PWB 2 with a new MCTL PWB 2.
Cause of Error
1. Failure of MCTL PWB 2.
CPU
EEPROM
C3
YES
YES
Cause of Error
1. Failure of MCTL PWB 2.
C4
YES
Clearance Method
1. Turn on and off the power switch.
2. Above method 1 does not work, implement "C3 Error Clearance Procedure".
3. Replace the failed MCTL PWB 2 with a new MCTL PWB 2.
NO
NO
Clearance Method
1. Turn on and off the power switch.
2. Replace the failed MCTL PWB 2 with a new MCTL PWB 2.
NO
Continue to drive the engine.
Continue to drive the engine.
Continue to drive the engine.