Brother MFC-J6935DW - Carriage Motor Cannot Stop; 4000 Casing Internal Thermistor Defective; Head Voltage Does Not Turn off; When Power Is on

Confidential
2-37
■ Error Code 3F00
Carriage motor cannot stop.
■ Error Code 4000
Casing internal thermistor defective
- Casing internal thermistor detects -20 degree-C or less, or 80 degree-C or more
when power is ON.
■ Error Code 4200
Head voltage does not turn OFF.
< User Check >
- They may occur due to lower surrounding temperature. Use in warmer surrounding
temperature.
Step Cause Solution
1 Carriage motor harness
connection failure
Reconnect the carriage motor harness.
2 CR encoder strip stained Clean the CR encoder strip.
3 CR encoder strip defective Replace the CR encoder strip.
4 CR encoder sensor defective Replace the carriage PCB ASSY.
5 Carriage motor defective Replace the carriage motor.
6 Main PCB defective Replace the main PCB.
Step Cause Solution
1 Casing internal thermistor
defective
Replace the ink refill ASSY.
2 Main PCB defective Replace the main PCB.
Step Cause Solution
1 Head flat cable connection
failure
Reconnect the head flat cable.
2 Carriage flat cable connection
failure
Reconnect the carriage flat cable.
3 Carriage PCB defective Replace the carriage PCB ASSY.
4 Head defective Replace the head/carriage unit.
5 Power supply PCB defective Replace the power supply PCB.
6 Main PCB defective Replace the main PCB.