Epson DFX-8500 Service Manual page 53

CHAPTER 2
OPERATING PRINCIPLES
2.1 PRINTER MECHANISM OPERATION__________________________________________ 2-1
Printhead Mechanism ______________________________________________________________________ 2-4
Carriage Mechanism_______________________________________________________________________ 2-5
Platen Gap Adjustment Mechanism ___________________________________________________________ 2-6
Paper Feed Mechanism _____________________________________________________________________ 2-7
Tractor Wire Operation___________________________________________________________________ 2-9
Ribbon Feed and Tractor Select Mechanisms___________________________________________________ 2-10
Plunger Mechanism ______________________________________________________________________ 2-12
2.2 POWER SUPPLY OPERATION _______________________________________________ 2-13
Power Supply Overview ___________________________________________________________________ 2-14
2.3 CONTROL CIRCUITS _______________________________________________________ 2-17
Control Circuit Operation Overview _________________________________________________________ 2-17
Reset Circuit ____________________________________________________________________________ 2-21
Sensor Circuits __________________________________________________________________________ 2-22
Carriage Motor Drive Circuit _______________________________________________________________ 2-26
Paper Feed Motor Drive Circuit _____________________________________________________________ 2-32
Ribbon Feed Motor Drive Circuit ____________________________________________________________ 2-34
Platen Gap Motor Drive Circuit _____________________________________________________________ 2-35
Plunger Drive Circuit _____________________________________________________________________ 2-37
Printhead Drive Circuit____________________________________________________________________ 2-38