CORVUS 7100-04702 User manual

THE CORVUS SERVICE MANUAL
Floppy Disk Drive
**. CORVUS SYSTEMS
* •

DISCLAIMER OF ALL WARRANTIES &LIABILITIES
Corvus Systems, Inc. makes no warranties, either expressed or implied, with respect to this
manual or with respect to the software described in this manual, its quality, performance, mer-
chantability, or fitness for any particular purpose. Corvus Systems, Inc. software is sold or
licensed lias is:' The entire risk as to its quality or performance is with the buyer and not Corvus
Systems, Inc., its distributor, or its retailer. The buyer assumes the entire cost of all necessary
servicing, repair, or correction and any incidental or consequential damages. In no event will
Corvus Systems, Inc. be liable for direct, indirect, incidental or consequential damages, even if
Corvus Systems, Inc. has been advised of the possibility of such damages. Some states do not
consequential damages, so the above limitation may not apply to you.
Every effort has been made to insure that this manual accurately documents the operation and
servicing of Corvus products. However, due to the ongoing modification and update of the soft-
ware along with future products, Corvus Systems, Inc. cannot guarantee the accuracy of printed
material after the date of publication, nor can Corvus Systems, Inc. accept responsibility for
errors or omissions.
NOTICE
Corvus Systems, Inc. reserves the right to make changes in the product described in this man-
ual at any time without notice. Revised manuals and update sheets will be published as needed
and may be purchased by writing to:
Corvus Systems, Inc.
2029 O'Toole Avenue
San Jose, CA 95131
Telephone: [phone]
TWX 910-338-0226
This manual is copyrighted and contains proprietary information. All rights reserved. This docu-
ment may not, in whole or in part be copied, photocopied, reproduced, translated or reduced to
any electronic medium or machine readable form without prior consent, in writing, from
Corvus Systems, Inc.
Copyright© 1982 by Corvus Systems, Inc. All rights reserved.
Mirror® patent pending, The Corvus Concept,"" Transporter,"" Corvus OMNINET,TM Corvus
Logicalc,"" Time Travel Editing,"" EdWord,"" Constellation,"" Corvus,"" Corvus Systems,"" Personal
Workstation,"" Tap Box,"" Passive Tap Box,"" Active Junction Box,"" Omninet Unit"" are trademarks
of Corvus Systems, Inc.
FCC WARNING
This equipment generates, uses, and can radiate radio frequency energy and if not installed and
used in accordance with the instruction manual, may cause interference to radio communica-
tions. As temporarily permitted by regulation it has not been tested for compliance with the
limits for Class A computing devices pursuant to Subpart Jof Part 15 of FCC Rules, which are
designed to provide reasonable protection against such interference. Operation of this equip-
ment in aresidential area is likely to cause interference in which case the user at his own
expense will be required to take whatever measures may be required to correct the interference.

CORVUS DEALER SERVICE
CORVUS SYSTEMS
CONCEPT PERSONAL WORKSTATION
8" FLOPPY DRIVE
SERVICE MANUAL
PART NO.: 7100-04702
DOCUMENT NO.: CCC/12-01/1.1
RELEASE DATE:
JULY 10, 1983
This document contains three types of notations. These are, in increasing order of importance, NOTE,
CAUTION, and WARNING. The NOTE indicates some action to be taken to speed or simplify a
procedure.
The CAUTION indicates that potential damage to the equipment or user data exists, and
care should be taken to avoid this. The WARNING indicates that potential harm or injury to the
service technicion or operator exists, and extreme care should be taken to avoid these.

CORVUS DEALER SERVICE
TABLE OF CONTENTS

CORVUS DEALER SERVICE
TABLE OF CONTENTS
List of Figures iii
List of Assembly Drawings and Schematics .......................................................... .. IV
Drive Specifications V
CHAPTER 1 - OVERVIEW
1.0 Scope of Manual. ............................................................. .. .......... .. 1
1.1
General Description. ...................................................................... .. 1
1.1.1 Drive
Assembly. ...................................... .. ........................ .. 1
1.1.2 Interface
Description. ............................................................ .. 1
1.2 Diskettes ................................. .. 1
1.2.1 Care and Handling of Diskettes 1
CHAPTER 2 - FUNCTIONAL DESCRIPTION
2.0 Scope of C:hapter ......................................................................... .. 3
2.1 Drive Mechanism. ........................................................................ .. 3
2.2 Block Diagram Description. .............. .. .............. .. ................... .. ........... .. 3
2.2.1 Index Pulse ..... ................................................................ .. 3
2.2.2 Drive Status Logic. .............................................................. .. 3
2.2.3 Spindle Drive Control. ...................... .. ................................... .. 3
2.2.4 Carriage Positioner Control 4
2.2.5 Write/Erase Control 4
2.2.6 Read Amplifier and Digitizer. ..................................................... .. 6
2.3 Concept Interface. ........................................................................ .. 7
CHAPTER 3 - DISASSEMBLY AND ASSEMBLY PROCEDURES
3.0 Scope of C:hapter ......................................................................... .. 9
3.1 Cover Disassembly and Assembly 9
3.2 :Power Supply Removal 10
3.3 :Power Harness Removal 10
3.4 :Rear ConIlectors and Devices 10
CHAPTER 4 - CHECKS AND ADJUSTMENTS
4.0 Scope of C:hapter 12
4.1 List of Tools 12
4.2 Drive Adjustments 12
4.2.1 Spindle Drive Motor -................................................. .. 12
4.2.2 Cats Eye Alignment 13
4.2.3 Head Carriage Adjustment 15
4.2.4 Index Sensor Checks and Adjustments 15
4.2.4.1 Index-To-Data Burst Check 15
4.2.4.2 Index Sensor Adjustment 16
4.2.4.3 Index Pulse Width Check 17
4.2.5 Track Zero Sensor Check and Adjustment 18
4.2.6 Amplitude Check 19
4.2.7 Azimith Check 20
4.2.8 Load Arm Adjustment 21

CORVUS DEALER SERVICE
4.3 Interface Controller Checks and Adjustments 21
4.3.1 Bias Voltage
Adjustment 22
4.3.2 Range Adjustment 22
4.3.3 Pre com p 22
4.4 Power Supply Adjustments ~ ~ 23
CHAPTER 5 - TROUBLESHOOTING
5.0 Scope of Chapter 24
5.1 Diagnostics 24
5.1.1 Operation 24
5.1.2 Test Descriptions 24
5.2 System Level Troubleshooting. ............................................................. .. 25
5.2.1 Interface Controller and Cable 26
5.2.2 Floppy Drive 26
5.2.3 Concept Workstation 26
5.3 Floppy Drive Unit 26
5.3.1 Power Supply 26
5.3.2 Diskette Drive Unit 27
5.3.3 Power Harness ; 27
5.4 Interface Controller Card 27
5.5 Troubleshooting Guide .................................................................... .. 28
APPENDICES
Appendix A
Appendix B
Appendix C
Appendix D
Glossary. ........................................................................ .. 30
Part Numbers .................................................................... .. 31
Schematic Diagrams 32
Assembly Drawings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38
ii

CORVUS DEALER SERVICE
LIST OF FIGURES

CORVUS DEALER SERVICE
LIST OF FIGURES
2-1 FunctioIlal Block Diagram 4
2-2 FM Recording Magnetization Profiles. .......................................... .. . . . . . . . . . .. 5
2-3 Write Operation Timing Diagram 6
2-4 Read Timing Diagram. . . . . . . . . . . .. . . . . . . . . . . .. ........................................... .. 7
3-1 Cover Installation 9
3-2 Drive Power Connector 10
3-3 Left Cover 11
4-1 Drive Circuit Board Assembly, Test Points 13
4-2 Hub Center Line and Track Locations 13
4-3 Cats Eye Pattern 14
4-4 Head Module Retaining and Cam Screws 15
4-5 Index-to-Data Burst 16
4-6 Index Sensor Retaining Screws and Adjustment ............................................. .. 17
4-7 Negative Going Pulse Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18
4-8 Track 00 Sensor Adjustment .............................................................. .. 18
4-9 Optimum Head Azimuth Alignment 20
4-10 Head Azimuth Acceptable Lower Limit 20
4-11 Head Azimuth Acceptable Upper Limit "21
4-12 Load
Arm Adjustment, Front View 21
4-13 Interface Controller Card 22
4-14 Power Supply Adjustments 23
5-1 Floppy [)rive Installation 25
5-2 Interface Controller Installation 26
iii

CORVUS DEALER SERVICE
LIST OF ASSEMBLY DRAWINGS AND SCHEMATICS

CORVUS DEALER SERVICE
'LIST OF ASSEMBLY DRAWINGS AND SCHEMATICS
Drive Schematics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 32
Controller Schematic 37
Assembly Drawings
Mechanism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38
Power Supply. ................................................................................... .. 39
Left Cover 0••••••••••••••••••••••••••••••••••••••• •• 40
DC Cable 41
Logic Board 42
Floppy Controller 43
iv