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TABLE OF CONTENTS


SECTION ONE:  INTRODUCTION ......................................                   1
   1.0   Overview ...............................................       1
   1.1   Main Components ........................................       1
   1.2   Case Design ............................................       1
   1.3   Power Supply ...........................................       3
   1.4   Negative Supplies ......................................       3

SECTION TWO:  THEORY OF OPERATION ...............................                   5
   2.0   Overview ...............................................       5
   2.1   Main System ............................................       5
   2.2   Audio/Video Subsystem ..................................       5
   2.3   Input/Output Subsystems ................................       6
   2.4   Microprocessing Unit ...................................       6
   2.5   GSTMCU .................................................       6
   2.6   Main Memory ............................................       7
   2.7   Direct Memory Access ...................................       8
   2.8   Multi-Function Peripheral Control ......................       8
   2.9   Audio/Visual Subsystem .................................       9
   2.10  Digitized Sound ........................................       11
   2.11  Genlock and the STE ....................................       11
   2.12  Input/Output Subsystems ................................       12
   2.13  System Startup .........................................       21
   2.14  System Errors ..........................................       22

SECTION THREE:  TESTING .........................................                   25
   3.1   Overview ...............................................       25
   3.2   Test Configuration .....................................       26
   3.3   Troubleshooting a Dead Unit ............................       26
   3.4   Diagnostic Cartridge ...................................       27
   3.5   Power Up Sequence ......................................       27
   3.6   Test Menu ..............................................       29
   3.7   RAM Test ...............................................       30
   3.8   ROM Test ...............................................       30
   3.9   Color Test .............................................       31
   3.10  Keyboard Test ..........................................       32
   3.11  MIDI Tests .............................................       33
   3.12  RS232 Tests ............................................       33
   3.13  Audio Test .............................................       34
   3.14  Timing Tests ...........................................       35
   3.15  DMA Tests ..............................................       35
   3.16  Floppy Disk Tests ......................................       36
   3.17  Printer and Joystick Port Tests ........................       38
   3.18  Monochrome Monitor .....................................       39
   3.19  Hard Disk Write/Read ...................................       39
   3.20  Graphics Chip BLiT .....................................       40
   3.21  Error Codes ............................. Quick Reference      40

SECTION FOUR: DISASSEMBLY/ASSEMBLY
   4.1   STE Disassembly ........................................       45
   4.2   STE Reassembly .........................................       46

SECTION FIVE: SYMPTOM CHECKLIST .................................
   5.1   Display Problems .......................................       49
   5.2   Disk Drive Problems ....................................       49
   5.3   Keyboard Problems ......................................       50
   5.4   MIDI Problems ..........................................       50
   5.5   RS232 Problems .........................................       50
   5.6   Printer Port Problems ..................................       50
   5.7   Hard Disk Port Problems ................................       50
   5.8   DMA Sound ..............................................       50

SECTION SIX: DIAGNOSTIC FLOWCHARTS ..............................
   6.1   Replacement Procedures .................................       51
   6.2   Handling of Integrated Circuits ........................       51

SECTION SEVEN: PARTS LIST .......................................                   57

SECTION EIGHT: GLOSSARY .........................................                   65

SECTION NINE:  SCHEMATICS AND SILKSCREENS .......................                   67