MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN
SERVICE MANUAL
6-43
I-11 Faulty
registration
Possible cause
Step
Check
Result
Remedy
Excessive paper
load
1
Is the paper loaded in the
paper tray more than 27mm
high?
Yes
Instruct the user to keep paper
loads below 27mm in depth.
Print paper
2
Is the specified weight of the
recommended paper being
used?
No
Recommend to use the
specified types of paper.
3
Is the first printing position
within ±1mm of the tolerance
specification?
Yes
Adjust the Y offset by using the
utility software supplied.
Rear regist
sensor position
incorrect
4
Is the position of the rear
registration sensor normal?
No
Reposition the sensor to the
correct position.
I-12 Poor
fixing
Possible cause
Step
Check
Result
Remedy
Print paper
1
Is thick paper of more than
43lb being used?
Yes
Recommend to use the
specified types of paper.
Toner sensing
failure
(When printing
is faint.)
2
Is the problem solved by
replacing the drum unit or the
toner cartridge?
Yes
1) Toner is empty.
2) The toner sensing is
defective. Clean the toner
sensor.
3) If the wiper in the toner
cartridge is broken, replace
the toner cartridge with a new
one.
Fixing unit
thermistor failure
3
Is the thermistor fitted
correctly?
No
Fit the thermistor correctly.
Low-voltage
power supply
PCB failure
4
Is the problem solved by
replacing the low-voltage
power supply PCB?
Yes
Replace the low-voltage power
supply PCB.
Summary of Contents for DCP-8020
Page 264: ...CHAPTER 7 MAINTENANCE MODE 7 6 Fig 7 3 l m a b c d e f g h i j k ...
Page 335: ...APPENDIX 4 CIRCUIT DIAGRAMS A 50 Appendix 4 1 Main PCB Circuit Diagram 1 6 ...
Page 337: ...APPENDIX 4 CIRCUIT DIAGRAMS A 52 Appendix 4 3 Main PCB Circuit Diagram 3 6 ...
Page 339: ...APPENDIX 4 CIRCUIT DIAGRAMS A 54 Appendix 4 5 Main PCB Circuit Diagram 5 6 ...
Page 341: ...APPENDIX 4 CIRCUIT DIAGRAMS A 56 Appendix 4 7 Driver PCB Circuit Diagram ...
Page 343: ...APPENDIX 4 CIRCUIT DIAGRAMS A 58 Appendix 4 9 Engine PCB Circuit Diagram 2 2 ...
Page 345: ...APPENDIX 4 CIRCUIT DIAGRAMS A 60 Appendix 4 11 NCU PCB Circuit Diagram Europe ...
Page 347: ...APPENDIX 4 CIRCUIT DIAGRAMS A 62 Appendix 4 13 NCU PCB Circuit Diagram Oceania ...