II-1
CHAPTER II THEORY
OF
OPERATION
1.
ELECTRONICS
1.1
General Block Diagram
<HL-720>
Fig. 2.1 shows a general block diagram of this printer.
Optional RAM board
(1.5, 3.5 Mbytes)
Expansion memory I/O
Control system
Video control block
Interface block
External device
Low-voltage power
supply block
High-voltage power
supply block
Engine control block
Operation block
(Operation panel)
Laser scanner unit
Transfer block
Drum unit
Developing
block
Cleaner
block
Drum
Charging
block
Toner cartridge
Image generation system
Paper tray unit
Erase lamp
Manual feed
Fixing unit
Paper eject block
Paper tray
Paper feed system
Drive block
(Stepping motor)
Fig. 2.1
Summary of Contents for HL-720
Page 1: ...SERVICE MANUAL MODEL HL 720 730 730Plus R LASER PRINTER ...
Page 36: ...II 19 1 3 10 Engine I O HL 720 Fig 2 21 shows the engine interface circuit Fig 2 21 ...
Page 37: ...II 20 HL 730 730Plus Fig 2 22 shows the engine interface circuit Fig 2 22 ...
Page 61: ... Fig 3 18 2 4 1 1 1 ...
Page 92: ...SERVICE MANUAL MODEL HL 760 R LASER PRINTER ...
Page 109: ...II 8 1 3 4 DRAM Two 4M bit DRAMs x 16bits are used as the RAM Fig 2 6 ...
Page 113: ...II 12 1 3 10 Engine I O Fig 2 12 shows the engine interface circuit Fig 2 12 ...
Page 114: ...II 13 1 3 11 Paper Feed Motor Drive Circuit Fig 2 13 ...
Page 133: ...Appendix 2 Main PCB Circuit Diagram 1 3 CODE UK3227000 B48K272CIR 1 3 NAME ...
Page 134: ...Appendix 3 Main PCB Circuit Diagram 2 3 CODE UK3227000 B48K272CIR 2 3 NAME ...
Page 135: ...CODE UK3227000 B48K272CIR 3 3 NAME Appendix 4 Main PCB Circuit Diagram 3 3 ...