Epson FX-870/1170 Printer Mechanism Operation, Printhead Mechanism

Principles of Operation 6

This chapter explains the mechanical and electrical operations of the FX-870/1170. At the end of the chapter, there are tables for component-level diagnosis of the main logic board and the power supply board.

Printer Mechanism Operation

This section describes the FX-870/1170 printer mechanism and explains how the printer works. The FX-870/1170 printer mechanism features a 9-pin impact dot printhead for serial printing. It has four main parts:

•the printhead mechanism

•the carriage movement mechanism

•the paper feed mechanism

•the ribbon advance mechanism

Each of these is described below.

Printhead Mechanism

The printhead mechanism consists of the printhead itself, the ink ribbon, and the platen. The printhead contains a column of 9 wires. Each of these wires has a drive coil, which causes the wire to move in and out of the printhead to print each dot. The three steps below describe how these driving wires work.

1.The control circuit outputs drive signals to the printhead drive circuit. This changes the printhead drive voltage, and current flows through the corresponding printhead coil. The coil acts as a solenoid and generates a magnetic force.

2.This induced force causes the plate to approach the coil rod, and the associated dot wire is rapidly ejected to impact on the platen.

3.The dot wire presses the ink ribbon up against the paper as it hits the platen, and in this way, prints a dot on the paper.

Epson FX-870/1170

6-1

Contents

I Revision Level FCC Compliance Statement Trademarks Epson FX-87W1170 Precautions 1 Printer Features 2 Installation and Setup Procedures 3 Troubleshooting software !Z’roubZeshooting 4 Disassembly/Assembly 5 Adjustments, Maintenance, and Lubrication 6 Principles of operation Principles of Operation ribbon Page Contents Epson FX-870.0170 Removing the Page List of Figures List of Tables Page EpsonFX-870/1170 Figure 1-1.External View of the FX-870/1170 Hardware Specifications Paper Handling Table l-l.Line Feed Speed (1 line = l/@ Precautions for Handling Paper Friction feed Push tractor feed Pull tractor feed Push-pulltractor feed Paper Specifications Normal Environmental Conditions Humidity:30 - 60 % RI-I Table 1-2. Specifications for Cut Sheets (Standard Paper) Table Table 1-4. Specifications for Continuous Paper Table 1-5. Specifications for Envelopes Table 1-6.Specifications for Labels Table 1-7.Specifications for Roll Paper Printable Area Area Figure 1-3.Printable Area for Cut Sheets Figure 1-4.Printable Area for Continuous Paper Figure 1-5. Printable Area for Roll Paper Ribbon Cartridge Electrical Specifications Table 1-8.Electrical Specifications for 120 V Model Environmental Conditions Table 1-9.Environmental Conditions Reliability Safety Approvals Firmware Specifications Print Control Table l-10.Character Size and Pitch W i d t h Interfaces Figure 1-6.Data Transmission Timing Table 1-13.Connector Pin Assignments and Signal Functions Return Signal Name Table 1-13.Connector Pin Assignments and Signal Functions (Cont.) signal No 9 to Optional Interfaces Table 1-14.Optional Interfaces Catalog W Interface Control Panel Micro Feed Function Bin Selection for the Cut Sheet Feeder Paper Ejection Indicators READY Table 1-15. Identification of Errors Using the LEDs Default Settings Table 1-17. Group 2 Features (ESC/P Mode) Character Table Table l-18.Group 2 Features (IBM Mode) COND L E D Power On Default Settings Table 1-19.Group 3 Features (Power-onSettings) Figure l-8. Self-TestPrintout l-8 Hexadecimal Dump Figure 1-9. Hexadecimal Dump Printout Paper-outDetection Auto Tear-off Buffer Full Printing Thermal Protection High-DutyPrinting Adjust Lever Operation Table l-20.Lever Positions I Lever Position Paber Thickness Figure l-10.Lever Positions Printer Initialization Note: Buzzer Table 1-21.Buzzer Functions Status Sound D e s c r i p t i o n Main Components C094 MAIN Board Assembly (Main Control Circuit Board) Figure 1-12.CO94 MAIN Board Assembly (Main Control Circuit Board) C094 PNL Board Assembly (Control Panel Circuit Board) C094 Figure 1-13.CO94 PNL Board Assembly CO94 (Control Panel Circuit Board) Printer Mechanism Figure l-16.Printer Mechanism Housing Assembly Commonly Asked Questions and Answers ribbons as Yes 8.Q. What is the part number for the printhead interface input buffer Q. How paper paths tractor multi-part paper Installation and Setup Site Requirements Removing the Packing Materials The Correct Power On Sequence Running the Self-Test Connecting Printer Cables 1 FGND ,l FGND :~.-x,xl Checking the Printer with the Computer Tips to Increase Printer Life Troubleshooting Test Points Table 3-2.Sensor Test Points Table 3-3.Motor Test Points and Coil Resistance Figure 3-1.Printhead Resistance Table 3-4.Printhead Test Points and Coil Resistance Table 3-5.Printhead Driver Test Points Table 3-6.Carriage and Paper Feed Motor Driver Test Points Error Codes Table 3-7.Error Codes Error Warning Error Cause Problem Isolation Table 3-8.Symptoms and Flowchart References (Continued) Serial Communications Errors Table 3-9.Identifying Serial Communications Errors Table 3-9.IdentiQing Serial Communications Errors (Continued) Problem Possible Cause and Chart 1. Printer Dead at Power On Chart 1. Printer Dead at Power On (Continued) Chart 2. Carriage Does Not Move or Moves Abnormally Chart 3. Paper Does Not Feed or Feeds Abnormally Chart 4. Poor Print Quality in Self-Test Chart 5. Ribbon Not Feeding Properly Chart 6. Data fhm Host is Printed Incorrectly Note: The host computer is assumed to be operating normally Chart 7. Page Length/Margins Incorrect Chart 8. Printout Double-Spaced Epson FX-870/i170 Connector Locations Sensor Locations Figure 3-5.Platen Gap Sensor Figure 3-6.Front and Rear PE Sensors Hex Quick Reference Table for ESC/P Commands Table 3-10.Hex. Codes for ESC/P Commands (Continued) Hex Quick Reference Table for IBM Commands Table 3-11.Hex. Codes for IBM Commands (Continued) Disassembly and Assembly Page Precautions Tools Table 4-1.Recommended Tools Table 4-2.Equipment Required for Maintenance Service Checks After Repair Table 4-3.Inspection Checklist for Repaired Printer QmwY Component items to Check Screw Specifications Table 4-4.Abbreviations Used for Screws Table 4-5.Screw Types and Abbreviations Notes for Unit Removal and Installation Items to Remove Before Disassembling the Printer Figure 4-2.Removing the Paper Guide Assembly Removing the Panel Unit Figure 4-3.Removing the Panel Unit Assembly Note Figure 4-4.Connecting the FFC Cable to the Panel Unit Removing the Printhead Figure 4-5.Removing the Printhead Removing the Upper Housing Assembly Upper Housing Assembly CBC/ (M4X15) \ Hooks Screwdriver Removing the Printer Mechanism Figure 4-7. Removing the Printer Mechanism Removing the Platen Assembly Figure 4-8.Removing the Platen Assembly Removing the Rear Frame Assembly 4 . Remove Remove the left frame Hexagon Nut /frfd??iA Removing the CR Motor Assembly 4-6.) CR Motor Assembly Face Screw (M3X7) +$@)-BeltTension Plate Removing the PF Motor Assembly Figure 4-12.Removing the PF Motor Assembly Disassembling the PF Gear Train Figure 4-13.Disassembling the PF Gear Train Figure 4-14.Positioning the Release Lever for Insertion Removing the Carriage Assembly Figure 4-15.Removing the Carriage Assembly Assembly Note Clip Timing Figure 4-16.Attaching the Timing Belt Removing the Ribbon Drive (RD) Assembly Figure 4-17.Removing the RD Assembly Removing the Home Position (HP) Sensor Figure 4-18.Removing the HP Sensor Removing the Platen Gap (PG) Sensor Figure 4-19.Removing the PG Sensor Removing the Front and Rear Paper End (PE) Sensors Figure 4-20. Removing the PE Sensors m-am1 Removing the Release Sensor Figure 4-21.Removing the Release Sensor Arranging the Cables Figure 4-22.Arranging the Cables Disassembling the Tractor Unit Figure 4-23.Disassembling the Tractor Unit Figure 4-24.Position of the Cog Removing the C094 MAIN Board Assembly Figure 4-25.Removing the CO94 MAIN Board Assembly Removing the C076 PSB Board Assembly NOTE Figure 4-26.Special Extractor Tool Figure 4-27.Removing the C076 PSB Board Assembly Adjustments, Maintenance, and Lubrication Adjusting the Printer Mechanism Figure 5-2.Parallelism Acijustment Bushing Figure 5-3.Platen Gap Bidirectional Alignment Adjustment Adjustment Operation Figure 5-4.Bidirectional Alignment Adjustment (Draft Mode) Figure 5-5.Bidirectional Alignment Adjustment (NLQ mode) Preventive Maintenance Lubrication Table 5-2.Lubrication Points Page Principles of Operation Page Page Printer Mechanism Operation Figure 6-1.How the Printhead Works Carriage Mechanism Figure 6-2.Carriage Operation Platen Adjustment PO Sensor Figure 6-3.Platen Gap Adjust Lever Paper Handling Mechanisms Paper Feed Mechanisms Table 6-1.Paper Feed Methods and Paper Entrances Paper Entrance Paper Feed Method Paper Advance Mechanisms You Figure 6-4.Friction Advance Operation Using the Top Paper Entrance Figure 6-5.Push Tractor Operation Using the Rear Paper Entrance Pthcipk of Operation Figure 6-6.Push Tractor Operation Using the Front Paper Entrance Figure 6-7.Pull Tractor Operation Using the Bottom Paper Entrance Figure 6-8. Push-pullTractor Operation Using the Rear Paper Entrance Figure 6-9. Push-pullTractor Operation Using the Front Paper Entrance The Release Lever Figure 6-10.Release Lever Figure 6-11.Release Lever Setting Functions Paper Paths Figure 6-12.Paper Path for Friction Feeding Using the Top Entrance for sensor Figure 6-13.Paper Path for Push Tractor Feeding Using the Rear Entrance Figure 6-14.Paper Path for Pull Tractor Feeding Using the Rear Entrance Paper Principles of Operation Figure 6-17.Paper Path for Friction Feeding Using the Front Entrance Figure 6-18.Paper Path for Push Tractor Feeding Using the Front Entrance Figure 6-19.Paper Path for Pull Tractor Feeding Using the Front Entrance Figure 6-20.Paper Path for Push-pullTractor Feeding Using the Front Entrance Ribbon Advance Mechanism Table 6-2.Ribbon Advance Gear Linkage Gear Linkage Figure 6-21.Ribbon Advance Mechanism Power Supply Operation Pfinciples of Operation Secondary Figure 6-22.Power Supply Circuit Block Diagram Control Circuit Operation Control Circuit Operation Overview Figure 6-24.Data Flow Table 6-5.Functions of Main Components of CO94 MAIN Reset Circuit Figure 6-25. Power On Reset Circuit Figure 6-26.Sensor Circuit Block Diagram Carriage Motor Drive Circuit Paper Feed Motor Drive Circuit CPU Figure 6-28.Paper Feed Motor Drive Circuit Printhead Drive Circuit CPU (IC2Cl) HEAD Figure 6-29.Printhead Drive Circuit Parallel Interface Circuit E2PROM Control Circuit B5A66YA (IC4) CPU (IC2Cl) Data Bus SCLSCK Component Repair Information (for Dealers Outside the U.S.) Table 6-7.Repairing the C076 PSB Board Assembly (Continued) Page Repairing the C094 MAIN Board Assembly Repairing Table 6-8.Repairing- the C094 MAIN Board Assembly Problem Symptom 4bnormal Table 6-8.Repairing the C094 MAIN Board Assembly (Continued) (QZ 4,5 Table 6-8.Repairing the C094 MAIN Board Assembly (Continued) Reference Materials Connector Summary CO76 PSB Figure 7-1.Cable Connections Table 7-1.CO94 MAIN Board Connector Summary Board Table 7-3.CN3, Front PE Sensor (CO94 MAIN Hoard Assembly) Table 7-6.CN6, Paper Feed Motor (CO64 MAIN Hoard Assembly) Table 7-7.CN7, Home Position Sensor Table 7-8.CNS, Printhead (CO94 MAIN Board Assembly) Table 7-10.CN12, Control Panel (CO94 MAIN Board Assembly) Table 7-11.CN13, CarA& Motor (CO94 MAlN Board Assembly) Circuit Diagrams Figure 73. C094 MAIN Board Assembly Circuit Diagram C076 PSB Power Supply Board CO76 PSB Power Supply Board Figure 7-6.CO94 PNL Board Assembly Circuit Diagram Circuit Board Component Layouts EPS-I Figure 7-8.CO76 PSB Board Assembly Component Layout Sw2 A S S Y 2 0 0 6 1 6 0 0 FL+ Figure 7-9.CO94 PNL Board Assembly Component Layout Epson F&870/1 380 ’ Figure 7-10. FX-870Case Outline Drawing Figure 7-11. F’X-1170Case Outline Drawing Page Index Index-2 Index-3 Index-4 Index-5 Index-8 Index-7 Page Index-9 Index-10 Index Index-11 Index-12 Index-13 Index-14