Brother HL-4040CN Service Manual page 34

Error code 3F
Print Unable 3F
Turn the power off and then back on again.
Writing error into engine program
Step
1 The machine is turned off
while rewriting the data into
the engine program.
Error code 56
Cover is Open
Close the Back Cover.
Back cover opened
User Check
- Check if the back cover is closed certainly.
Step
1 Back cover switch failure
2 Harness connection failure of
back cover switch ASSY
3 Part pressing the back cover
switch is broken, which is
provided at the right side of
back cover inside.
4 Engine PCB failure
Error code 57
Jam Duplex
Pull out Tray 1 completely. Check inside the machine or open the Back
Cover to remove the jammed paper.
Paper jam while turning it over in duplex printing, or DX solenoid failure
User Check
- Check if the paper is jammed or not. If jammed, remove it.
Step
1 DX feed ASSY not assembled
correctly
2 Paper eject ASSY harness
connection failure
3 DX solenoid failure
4 Engine PCB failure
Cause
Turn the power on. Resend the engine program
data (DJF format) with the USB memory while the
error code is being indicated.
Cause
Check the sensor performance following the
procedure described in
Check the harness connection of the back cover
switch ASSY and reconnect it.
Replace the back cover switch ASSY.
Replace the engine PCB ASSY.
Cause
Reassemble the DX feed ASSY.
Check the harness connection of the paper eject
ASSY and reconnect it.
Replace the paper eject ASSY.
Replace the engine PCB ASSY.
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Remedy
Remedy
"Maintenance mode
Remedy
Confidential
32".