Epson 670 2.1.5 Platen Gap Adjustment

Chapter 2 Operating Principles

Rev. A

2-1

0

2.1.5 Platen Gap Adjustment

Platen gap (the gap between platen surface and print head) allows the printer to use different thickness of

paper by setting appropriate gap so that the different thickness of paper can avoid getting printing dirt or

picking the ribbon accidentally. Adjustment mechanism consists of the CR guide shaft, parallelism

adjustment bush, adjust lever and PG detector.

The rotating center of the CR guide shaft is angled to the rotating center of the adjust lever. Rotating the

adjust lever enables the print head to get closer to or away from the platen surface. The parallelism

adjustment bush should set the CR guide shaft parallel to the platen surface. The PG detector detects the

position of the adjust lever and changes the printing speed to the copy mode when using the thick paper

and setting the adjust lever more than 2 levels.

Category Specification

Type Mechanism Type

Switch Rating 0.6∼1.0mA, 5VDC±5%

Switch Mode Normal Mode : Open

Copy Mode : Short (more than 2 levels)

Adjsut Lever

CR Guide Shaft

Print Head

Rotation Center of the CR Guide Shaft

PG Detector

Figure 2-7. Platen Gap Adjustment Mechanism

Table 2-10. PG Detector Specification

Contents

Main NOTICE Copyright 1997 by SEIKO EPSON CORPORATION Nagano, Japan PRECAUTIONS WARNING CAUTION WARNING CAUTION PREFACE Page Page Chapter 1 Product Descriptions 1.1 Specifications 1.1.1 Features Page 1.2 Hardware Specifications 1.2.1 Printing Method 1.2.2 Printing Specifications Rev. A 1- 1.2.3 Paper Handling Specifications 1.2.4 Paper Specification Rev. A 1- Note1) Note3): Note2): Note2): Page Page 1.2.5 Printable Area Rev. A 1-11 Note *1) Printable Area Printable Area BM 1.2.6 Ribbon Cartridge 1.2.7 Input data buffer Note*) 1.2.8 Electrical Specification 1.2.9 Reliability 1.2.10 Environmental Condition 1.2.11 Safety Approvals 1.2.12 CE Marking 1.2.13 Acoustic Noise 1.3 Firmware Specification 1.3.1 Control Codes and Fonts Page 1.3.2 Interface Specification 1.3.2.1 Parallel interface (Forward channel) Page 1.3.2.2 Parallel Interface (Reverse channel) Note*): Rev. A 1-21 1.3.2.3 Optional Interface 1.3.2.4 Interface Selection 1.3.3 Prevention Hosts from Data Transfer Timeout 1.4 Operation 1.4.1 Control Panel 1.4.1.1 Usual Operation Page 1.4.1.2 Switches 1.4.1.3 Indicators(LED) 1.4.1.4 Buzzer 1.4.2 Default Setting Notes. 1.4.3 Bi-d Adjustment 1.4.4 Initialization 1.4.5 Errors 1-3 1.5 Main Components 1.5.1 C214 Main Board 1.5.2 C214PSB Board Page Chapter 2 Operating Principles Rev. A 2-1 2.1 Printer Mechanism Operation 2.1.1 Printing Mechanism Page 2.1.2 Carriage Mechanism Page 2.1.3 Ribbon Advance Mechanism 2- 2.1.4 Paper Advance Mechanism 2.1.4.1 Paper Advance Mechanism 2.1.4.2 Paper Advance Detector Mechanism Page 2.1.4.3 Release Lever Mechanism Release Lever Tractor Gear Roller, PF Drive Tractor Transmission Gear 2.1.5 Platen Gap Adjustment Rev. A 2-11 2.2 Power Supply Operation 2.2.1 Power Supply Circuit 2.2.1.1 Power Supply Overview 2.2.1.2 Power Supply Circuit Operation Rev. A 2-1 2.2.2 Control Circuit 2.2.2.1 Operating Principles of the Control Circuit 2.2.2.2 EEPROM Control Circuit 2.2.2.3 System Reset Circuit 2.2.2.4 Power Off Detector Circuit 2.2.2.5 Print Head Driver Circuit 2.2.2.6 CR Motor Driver Circuit 2.2.2.7 PF Motor Driver Circuit 2.2.2.8 Operation Panel Control Circuit Page Chapter 3 Disassembly and Assembly Page 3.1 Overview 3.1.1 Precautions for Disassembling the Printer 3.1.2 Tools WARNING 3-2 3.1.3 Service Check After Repair 3.1.4 Specifications for Screws 3-4 3.2 Printer Disassembly and Assembly Figure 3-1. Disassembly Flowchart The flowchart below show you the basic order for disassembly. Before disassembling any part of the printer, note the warnings in Section 3.1.1. START 3.2.1 HOUSING, UPPER Removal 3-6 3.2.2 Printer Mechanism Removal 3.2.3 C214 MAIN Board Removal 3.2.4 C214 PSB/PSE Board Removal 3.2.5 EP-ROM Replacement CHECK POINT 3.2.6 Printhead Removal 3.2.7 Ribbon Mask Removal 3.2.8 PAPER EXIT ASSY. Removal 3.2.9 Ribbon Mask Holder Removal 3.2.10 PW Detector (Top) Removal 3.2.11 MOTOR, CR Removal 3.2.12 Carriage Assy. Removal CHECK POINT Page 3.2.12.1 RATCHET, RD Removal 3.2.13 PAPER GUIDE Removal Page Chapter 3 Disassembly and Assembly Rev. A 3-21 3-22 3.2.14 Platen Removal 3.2.15 MOTOR, PF Removal Page 3.2.19 DETECTOR, PE, FRONT Removal 3.2.20 DETECTOR, PE, REAR Removal 3.2.21 LEVER, RELEASE Removal 3.2.22 Tractor ASSY. Removal Page Rev. A 4-1 4.1 Adjustment Overview Note*2) Note*1) 4.1.1 Required Adjustments 4.1.2 Required Adjustment Tools 4.2 Adjusting and Resetting the Printer Do not rotate the platen roller during this adjustment. 4.2.1 Platen Gap Adjustment Rev. A 4- 4.2.2 Factory Setting Page Rev. A 4- 4.2.3 Bi-d Adjustment Page Page 5.1 Overview 5- 5.2 Unit Level Troubleshooting Page Page Page Page Rev. A 5- Page View A R F R L 1-24 :Wire Number C :Common Terminal T:Thermistor Terminal Note*) Rev. A 5-11 5.3 Repairing the Power Supply Circuit Board Page Page 5.4 Repairing the Main Board Page Page 5.5 Repairing the Printer Mechanism Page Page 6.1 Preventive Maintenance Page Appendix A.1 Connector Summary A- Rev. A A- A- Page Page Page Page Page Page Page Page Page A-1 Page A.5 Dimension and Weight EPSON OVERSEAS MARKETING LOCATIONS As of September, 1996