MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN
SERVICE MANUAL
6-39
I-5
Dirt on the back of paper
Possible cause
Step
Check
Result
Remedy
Fixing unit dirty
1
Is the pressure roller dirty?
Is any other area in the
machine dirty?
Yes
Clean the pressure roller
referring to the following
procedure.
Dirt in the drum
unit
2
Is the transfer roller dirty?
Is the problem solved after
replacing the drum unit?
Yes
Replace the drum unit
No
Replace the high-voltage power
supply PCB.
NOTE:
This problem may disappear after printing approximately 10 pages of completely blank sheets.
How to clean the pressure roller
Clean the pressure roller as follows
(1) Set ten or more sheets of paper in the paper tray.
(2) Check the absence of paper in the ADF and the paper tray.
(3) Press
Copy
button to copy and repeat it five times.
(4) Check whether any stain are observed on the back of paper or not.
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 ...