ENCAD CADJET 2 Service Manual page 8

Table of Contents
CHAPTER 2
Mechanical overview and electrical circuitry theory with block diagram
visuals.
1.0 Introduction ....................................................................................................... 2-1
2.0 Mechanical Operation ....................................................................................... 2-2
2.1 Media Axis Drive .................................................................................. 2-2
2.2 Carriage Axis Drive .............................................................................. 2-2
3.0 Electrical Operation........................................................................................... 2-3
3.1 Circuit Assemblies ............................................................................... 2-3
3.1.1
3.1.2
3.1.3
3.2 Block Diagram ..................................................................................... 2-5
3.3 Power Supply....................................................................................... 2-6
3.4 Microprocessor .................................................................................... 2-7
3.5 Start-up Sequence............................................................................... 2-8
3.6 Memory................................................................................................ 2-9
3.7 Flash EPROM.................................................................................... 2-10
3.8 RAM................................................................................................... 2-11
3.9 EEPROM ........................................................................................... 2-11
3.10 Gate Array ......................................................................................... 2-12
3.11 Stepper Motor .................................................................................... 2-13
3.12 Servo Motor ....................................................................................... 2-15
3.13 Parallel and Serial Ports .................................................................... 2-16
3.14 Keypad/Display.................................................................................. 2-17
3.15 Carriage Circuits ................................................................................ 2-18
3.16 LED's, Beeper, and Fan .................................................................... 2-19
3.17 Dot Firing Sequence .......................................................................... 2-19
3.18 Schematic Diagrams.......................................................................... 2-19
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THEORY OF OPERATION
Main Printed Circuit Board (MPCB) ..................................... 2-3
Front Panel Circuit ............................................................... 2-3
Carriage Printed Circuit Assembly (Carriage PCB).............. 2-4
CADJET 2