I-6
Black vertical streaks
Black and blurred vertical stripes
Possible cause
Step
Check
Result
Remedy
Drum unit
failure
1
Are the vertical streaks about 1 - 5
length at 94mm intervals?
Yes
Replace the drum
unit.
Soiling of the
paper feed
system
2
Is the paper tray of feed system on
the drum unit soiled with toner?
Yes
Clean the toner off.
Corona failure
3
Are the vertical block streak about
10mm width?
Has the corona wire cleaner failed
to return to its home position?
Yes
Return the wire
cleaner or its home
position.
Corona failure
4
Is the corona wire soiled?
Yes
Clean the corona
wire.
Scanner
window
5
Is the scanner window dirt?
Yes
Clean the scanner
window with a soft
dry cloth.
Scratch on the
drum
6
Remove the transfer roller.
Is the surface of the drum
scratched?
Yes
Replace the drum
unit.
Cleaning failure
7
Is the drum surface soiled in
streaks?
Yes
Replace the drum
unit.
Scratch on the
fixing unit
8
Is the drum surface still soiled in
streaks even after replacing the
drum unit?
Yes
Replace the fixing
unit.
Содержание HL-720
Страница 1: ...SERVICE MANUAL MODEL HL 720 730 730Plus R LASER PRINTER ...
Страница 36: ...II 19 1 3 10 Engine I O HL 720 Fig 2 21 shows the engine interface circuit Fig 2 21 ...
Страница 37: ...II 20 HL 730 730Plus Fig 2 22 shows the engine interface circuit Fig 2 22 ...
Страница 61: ... Fig 3 18 2 4 1 1 1 ...
Страница 92: ...SERVICE MANUAL MODEL HL 760 R LASER PRINTER ...
Страница 109: ...II 8 1 3 4 DRAM Two 4M bit DRAMs x 16bits are used as the RAM Fig 2 6 ...
Страница 113: ...II 12 1 3 10 Engine I O Fig 2 12 shows the engine interface circuit Fig 2 12 ...
Страница 114: ...II 13 1 3 11 Paper Feed Motor Drive Circuit Fig 2 13 ...
Страница 133: ...Appendix 2 Main PCB Circuit Diagram 1 3 CODE UK3227000 B48K272CIR 1 3 NAME ...
Страница 134: ...Appendix 3 Main PCB Circuit Diagram 2 3 CODE UK3227000 B48K272CIR 2 3 NAME ...
Страница 135: ...CODE UK3227000 B48K272CIR 3 3 NAME Appendix 4 Main PCB Circuit Diagram 3 3 ...