Epson FX-870 Service Manual page 113

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