Epson FX-870/1170 - Manual (Page 113)

Principles of Operation
Chapter 6
Principles of Operation
Printer Mechanism Operation ................................................................. 6-1
Printhead Mechanism ...................................................................... 6-1
Carriage Mechanism ........................................................................ 6-3
Platen Gap Adjustment ................................................................... 6-4
Paper Handling Mechanisms .......................................................... 6-5
Paper Feed Mechanisms ........................................................ 6-5
Paper Advance Mechanisms .................................................. 6-6
The Release Lever ................................................................
6-12
Paper Paths .......................................................................... 6-13
Ribbon Advance Mechanism.......................................................... 6-18
Power Supply Operation ........................................................................ 6-19
Power Supply Overview ................................................................. 6-19
Power Supply Circuit Operation ................................................... 6-19
Control Circuit Operation ...................................................................... 6-22
Control Circuit Operation Overview ............................................. 6-22
Reset Circuit ..................................................................................
6-25
Sensor Circuits ............................................................................... 6-26
Carriage Motor Drive Circuit ........................................................ 6-27
Paper Feed Motor Drive Circuit .................................................... 6-28
Printhead Drive Circuit .................................................................
6-29
Parallel Interface Circuit ............................................................... 6-29
Control Circuit ................................................................ 6-30
Component Repair Information (for Dealers Outside the U.S.).. 6-31
Repairing the C076 PSB Board Assembly ........................... 6-31
Repairing the C094 MAIN Board Assembly........................ 6-34
List of Figures
Figure 6-1. How the Printhead Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Figure 6-2 . Carriage Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-3
Figure 6-3. Platen Gap Adjust Lever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Figure 6-4. Friction Advance Operation Using the
Top Paper Entrance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Figure 6-5. Push Tractor Operation Using the Rear Paper Entrance ........ 6-7
Figure 6-6. Push Tractor Operation Using the Front
Paper Entrance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Figure 6-7. Pull Tractor Operation Using the Bottom Paper
Entrance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
Epson FX-870/1170 6-i