Brother HL-4140CN Service Manual page 70

■ Error code 50
Replace Drum
Drum unit is at the end of life.
Error code 51
Replace PF Kit MP
MP paper feeding kit is at the end of life.
Error code 52
Replace PF Kit1
Paper feeding kit1 is at the end of life.
Error code 53
Replace PF Kit2
Paper feeding kit2 is at the end of life.
Error code 54
Replace Fuser
Fuser unit is at the end of life.
Error code 55
Replace Laser
Laser unit is at the end of life.
Step
1 The part displayed on the LCD
reached the end of life.
2 Main PCB failure
Cause
2-39
Remedy
Replace the part displayed on the LCD
and reset the counter of each part.
(Refer to "2.3 Parts Life Reset Function" in
Chapter 5.)
Replace the main PCB ASSY.
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