Brother International HL-720 Service Manual - Page 96

CONTENTS CHAPTER I FEATURES AND SPECIFICATIONS I-1 1. FEATURES ...I-1 2. SPECIFICATIONS ...I-3 2.1 Printing...I-3 2.2 Functions ...I-3 2.3 Electrical and Mechanical ...I-4 2.4 Paper Specification Refer to HL-730 (P.I-7) 2.5 Print Delivery Refer to HL-730 (P.I-7) 2.6 Paper ...Refer to HL-730 (P.I-7) 2.7 Effective Printing Area Refer to HL-730 (P.I-8) 3. SAFETY INFORMATION REFER TO HL-730 (P.I-10) 3.1 Laser Safety (110 - 120V Model only Refer to HL-730 (P.I-10) 3.2 CDRH Regulations (110 -120V Model only Refer to HL-730 (P.I-10) 3.3 Caution for Laser Product Refer to HL-730 (P.I-11) CHAPTER II THEORY OF OPERATION II-1 1. ELECTRONICS...II-1 1.1 General Block Diagram...II-1 1.2 Main PCB Block Diagram ...II-2 1.3 Main PCB...II-3 1.3.1 CPU Core ...II-3 1.3.2 ASIC ...II-4 1.3.3 ROM ...II-7 1.3.4 DRAM ...II-8 1.3.5 Optional RAM ...II-9 1.3.6 Optional Serial I/O ...II-10 1.3.7 EEPROM ...II-10 1.3.8 Reset Circuit ...II-11 1.3.9 CDCC I/O ...II-11 1.3.10Engine I/O...II-12 1.3.11Paper Feed Motor Drive Circuit II-13 1.4 Panel Sensor PCB Refer to HL-730 (P.II-22) 1.5 Power Supply Refer to HL-730 (P.II-23) 2. MECHANICS REFER TO HL-730 (P.II-24) 2.1 Overview of printing mechanism Refer to HL-730 (P.II-24) 2.2 Paper Transfer Refer to HL-730 (P.II-25) 2.2.1 Paper Supply Refer to HL-730 (P.II-25) 2.2.2 Paper Registration Refer to HL-730 (P.II-25) 2.2.3 Paper Eject Refer to HL-730 (P.II-26) 2.3 Sensors Refer to HL-730 (P.II-27) 2.3.1 Cover Sensor Refer to HL-730 (P.II-27) 2.3.2 Toner Empty Sensor Refer to HL-730 (P.II-27) 2.4 Drum Unit Refer to HL-730 (P.II-28) 2.4.1 Photosensitive Drum Refer to HL-730 (P.II-28) 2.4.2 Primary Charger Refer to HL-730 (P.II-28) 2.4.3 Developer Roller Refer to HL-730 (P.II-28) 2.4.4 Transfer Roller Refer to HL-730 (P.II-28) i