Tektronix 2440 User manual

TEK 070-6603-00
Product Group 37
2440
OSCILLOSCOPE
SERVICE
WARNING I
/the following servicing instructions are
*'for use by qualified personnel ONLY.- to
AVOID PERSONAL INJURY, DO NOT PERFORM ANY
SERVICING OTHER THAN THAT CONTAINED IN
OPERATING INSTRUCTIONS UNLESS YOU ARE
QUALIFIED TO DO SO. REFER TO OPERATORS
SAFETY SUMMARY AND SERVICE SAFETY SUM-
MARY PRIOR TO PERFORMING ANY SERVICE.
Please Check for
CHANGE INFORMATION
at the Rear of This Manual
First Printing JUL 1988
Revised JUN 1989 Tfektronix
COMMITTED TO EXCELLENCE

Copyright ©1588 Tektronix, Inc. Ail rights reserved. Contents of this
publication may not be reproduced in any form without the written
permission of Tektronix, Inc.
Products of Tektronix, Inc. and its subsidiaries are covered by U.S.
and foreign patents and/or pending patents.
TEKTRONIX, TEK, SCOPE-MOBILE, and
trademarks of Tektronix, Inc.
are registered
Printed in U.S.A. Specification and price change privileges are
reserved.
Instrument Serial Numbers
Each instrument has aserial number on apanel insert, tag, or
stamped on the chassis. The first number or letter designates the
country of manufacture. The last five digits of the serial number are
assigned sequentially and are unique to each instrument. Those
manufactured in the United States have six unique digits. The country
of manufacture is identified as follows:
BOOOOOO Tektronix, Inc., Beaverton, Oregon, USA
100000 Tektronix Guernsey, Ltd., Channel Islands
200000 Tektronix United Kingdom, Ltd., London
300000 Sony/Tektronix, Japan
700000 Tektronix Holland, NV, Heerenveen.The Netherlands

2440 Service
TABLE OF CONTENTS
Page
LIST OF ILLUSTRATIONS iii
LIST OF TABLES v
OPERATORS SAFETY SUMMARY vi
SERVICING SAFETY SUMMARY vii
Section 1SPECIFICATION
INTRODUCTION 1-1
PERFORMANCE CONDITIONS .. 1-4
Section 2PREPARATION FOR USE
SAFETY 2-1
LINE VOLTAGE SELECTION 2-1
LINE FUSE 2-1
POWER CORD 2-3
INSTRUMENT COOLING 2-3
START-UP !2-3
POWER-DOWN 2-4
REPACKAGING FOR SHIPMENT 2-4
Section 3THEORY OF OPERATION
SECTION ORGANIZATION 3-1
INTEGRATED CIRCUIT
DESCRIPTIONS 3-1
SIMPLIFIED BLOCK DIAGRAM
DESCRIPTION 3-2
DETAILED BLOCK DIAGRAM
DESCRIPTION 3-8
INTRODUCTION 3-8
INPUT SIGNAL CONDITIONING
AND ANALOG SAMPLING 3-8
ACQUISITION PROCESS
AND CONTROL 3-10
DATA CLOCKING TO
ACQUISITION MEMORY 3-10
ANALOG DATA CONDITIONING
AND A/D CONVERSION 3-11
ACQUISITION PROCESSING
AND DISPLAY 3-12
DETAILED CIRCUIT
DESCRIPTION 3-15
SYSTEM PROCESSOR 3-15
WAVEFORM PROCESSOR
SYSTEM 3-22
Page
FRONT PANEL PROCESSOR 3-28
FRONT PANEL CONTROLS 3-30
SYSTEM DAC AND ACQUISITION
CONTROL REGISTERS 3-31
SYSTEM DAC (cont) AND
AUXILIARY FRONT PANEL 3-33
SYSTEM CLOCKS 3-35
TIME BASE CONTROLLER
AND ACQUISITION MEMORY 3-39
ATTENUATORS AND
PREAMPLIFIERS 3-43
PEAK DETECTORS AND
CCD/CLOCK DRIVERS 3-45
TRIGGERS AND PHASE CLOCKS 3-51
JITTER CORRECTION RAMPS 3-56
TRIGGER HOLDOFF, JITTER
COUNTERS, AND CALIBRATOR 3-58
CCD OUTPUT 3-61
A/D CONVERTER AND
ACQUISITION LATCHES ,3-62
DISPLAY AND ATTRIBUTES
MEMORY 3-63
DISPLAY CONTROL 3-66
DISPLAY OUTPUT 3-73
HIGH VOLTAGE POWER
SUPPLY AND CRT 3-75
SYSTEM I/O 3-80
VIDEO OPTION 3-84
LOW VOLTAGE POWER SUPPLY 3-92
LOW VOLTAGE REGULATORS 3-98
Section 4PERFORMANCE CHECK AND
FUNCTIONAL VERIFICATION
PROCEDURE
INTRODUCTION 4-1
PREPARATION 4-1
INITIAL SETUP.... 4-4
VERTICAL SYSTEM 4-6
TRIGGERING SYSTEMS..... 4-18
HORIZONTAL SYSTEM 4-26
ADDITIONAL VERIFICATIONS
AND CHECKS 4-29

2440 Service
TABLE OF CONTENTS (cont)
Section 5ADJUSTMENT PROCEDURE Page
DIAGNOSTICS AND
Page
INTRODUCTION ..U.
CALIBRATION SEQUENCE AND ... 5-1 INTERNAL CALIBRATION
ROUTINES. ROR
PARTIAL PROCEDURES
.
... 5-1 INTRODUCTION ft OC
WARM-UPTIME REQUIREMENT...,... 5-1 OVERVIEW R-2R
PRESERVATION OF CALIBRATION ROUTINES
DIAGNOSTIC ROUTINES 6-25
—INSTRUMENT™ •
6-27
CALIBRATION ... 5-2 DIAGNOSTICS OPERATION
INTERNAL ADJUSTMENTS ... 5-3 VIA THE GPIB INTERFACE. 6-34
SELF CALIBRATION.... ,. 5-19 DIAGNOSTIC PROCEDURES 6-35
EXTERNAL CALIBRATION .. 5-20
Section 6MAINTENANCE
INSTRUMENT CALIBRATION 6-1
NATIONAL BUREAU OF
STANDARDS TRACEABILITY 6-2
VOIDING CALIBRATION .6-2
STATIC-SENSITIVE COMPONENTS 6-3
PREVENTIVE MAINTENANCE 6-4
INTRODUCTION...... 6-4
GENERAL CARE..... 6.4
INSPECTION AND CLEANING 6-4
LUBRICATION....... 6-6
SEMICONDUCTOR CHECKS 6-6
PERIODIC READJUSTMENT 6-6
TROUBLESHOOTING 6-7
INTRODUCTION ’. 6-7
TROUBLESHOOTING AIDS 6-7
TROUBLESHOOTING
EQUIPMENT 6-9
TROUBLESHOOTING
TECHNIQUES 6-9
CORRECTIVE MAINTENANCE 6-11
INTRODUCTION.... 6-11
MAINTENANCE PRECAUTIONS 6-11
OBTAINING REPLACEMENT
PARTS. 6-11
MAINTENANCE AIDS.... 6-12
INTERCONNECTIONS 6-12
TRANSISTORS AND
INTEGRATED CIRCUITS 6-12
SOLDERING TECHNIQUES 6-14
REMOVAL AND REPLACEMENT
PROCEDURE 6-15
Section 7OPTIONS AND ACCESSORIES
OPTIONS DESCRIPTION...
OPTIONS A1-A5—INTERNATIONAL
POWER CORDS .
OPTION 1R—RACKMOUNTED
2440
.. 7-1
.. 7-1
7-1
OPTION 03—WORD
RECOGNIZER PROBE .7-2
OPTION 05—VIDEO OPTION .7-2
OPTION 11—PROBE POWER .7-2
STANDARD ACCESSORIES .7-2
RA'CKMOUNTING ACCESSORIES.....7-2
OPTIONAL ACCESSORIES.... .7-2
Section 8REPLACEABLE ELECTRICAL PARTS
Section 9DIAGRAMS
Section 10 REPLACEABLE MECHANICAL PARTS
CHANGE INFORMATION
Diagnostic and Troubleshooting information:
Diagnostics 6_25
Diagnostic Operation 6-30
Diagnostic Procedures........ 6-32
2440 Troubleshooting Procedures Table 6-35
Video Option Troubleshooting Table 6-99
Troubleshooting Charts Section 9
ii

2440 Service
LIST OF ILLUSTRATIONS
Figure Pa9®
The 2440 Digital Oscilloscope viii
1-
1Dimensional drawing 1-24
2-
1LINE VOLTAGE SELECTOR, line fuse, and power cord receptacle :2-1
3-
12440 simplified block diagram 3-3
3-2 Simplified Memory Map of the 2440 3-18
3-3 System Clock waveforms 3-37
3-4 Simplified Peak Detector block diagram --3-47
3-5 Simplified CCD architecture —3-49
3-6 Trigger Logic Array Control Data Byte 3-53
3-7 Jitter correction waveforms 3-57
3-8 Readout State Machine flow chart 3-71
3-9 Vertical Vector Generator 3-73
3-10 DC Restorer 3-78
3-11 GPIB data flow diagram 3-81
3-12 GPIB three-wire handshake state diagram 3-82
3-13 Video Option waveforms 3-87
3-14 Video Option field-sync identification 3-88
3-15 'PWM Regulator and Inverter 3-94
3-16 PWM switching waveforms •• 3-96
5-1 Adjustment locations for Displays 4through 65-4
5-2 Display 5—Vertical and Horizontal Gain, Offset, and Vector
Compensation adjustment pattern 5-5
5-3 Display 6—Integrator Time adjustment pattern 5-6
5-4 (SN B010250 &Above) CH 1and CH 2CCD Clock Adjustments
(shown centered, as after doing part b) 5-7
5-4 (SN B010249 &Below) CH 1and CH 2CCD Clock Adjustments
(shown centered, as after doing part b) 5-8
5-5 CCD counts display and CM adjustment menu 5-8
5-6 CCD sides 1-4 for CH 1before L-clock adjustment 5-12
5-7 Sides 1and 3 before adjustment of LIS and after 5-13
5-8 CH 1with L-clocks correctly adjusted, but with stray samples 5-14
5-9 Display for adjusting CCD Aand Tclocks •5-15
5-1 0Typical CH 1and CH 2displays after clock adjustment 5-1
6
5-11 Checking sample dispersion 5-17
5-
12 Input and output (after adjustment) waveforms 5-20
6-
1Multipin connector 6-8
6-2 Circuit board Location 6-1 6
6-3 Installation sequence for installing the crt frame screws 6-23
6-4 Trigger LED binary coding for diagnostic tests 6-29
6-5 Main EXT DIAG Menu 6-30
6-6 Initial troubleshooting chart *6-36
6-7 Mux Test waveforms 6-41

2440 Service
LIST OF ILLUSTRATIONS (cont)
Page
6-8
6-9
6-10
9-1
9-2
9-3
9-4a
9-4b
9-5
9-6
9-7
9-8
9-9
9-10
9-11
9-12
Typical Register test waveforms
Front Panel ftP diagnostics test..
System fiP data bit D7 in the Bus Isolate mode
Color codes for resistors and- capacitors. * - —~———-———-
Semiconductor lead configurations.
Locating components on schematic diagrams and circuit board illustrations.
Detailed 2440 Block Diagram.
Detailed 2440 Block Diagram (cont).
A12—Processor Board.
A13—Side Board. !
A14—Front Panel Board.
A10—Main Board.
A30, A31, A32 and A33— Gain Cell Boards.
A1 1—Timebase/Display Board.
A17—High Voltage Board.
A16—Low Voltage Power Supply Board.
(
IV

2440 Service
LIST OF TABLES
Table Page
1-1 Electrical Characteristics
1-2 Environmental Characteristics
1-3 Mechanical Characteristics
1-4 Option 05 (TV Trigger) Electrical Characteristics
2-1 Voltage, Fuse, and Power-Cord Data
3-1 Host Memory-Mapped I/O
3-2 Processor Control Register Functions
3-3 Processor Miscellaneous Register (PM REG) Output Functions...
3.4 Waveform pPAddress Decoding
3-5 Trigger Logic Array Addresses (6080h-6087h)
3-6 Phase Clock Array Control Lines (CC3 through CCO)
3-7 Holdoff Delay Range for Current Source vs Charging Capacitor
Combinations
3-8 Side Board Address Decoding
3-20
3-21
3-22
3-27
3-52
3-55
3-59
3-60
4-1 Test Equipment Required
4-2 Accuracy Limits CH 1and CH 2CURSOR VOLTS Readout and Aand
BTRIGGER LEVEL Readouts .
4-3 Minimum Display Level for CH 1or CH 2Triggering
4_4 Minimum Signal Level for EXT1 or EXT2 Triggering
6-1 Relative Susceptibility to Static-Discharge Damage
6-2 External Inspection Check List
6-3 Internal Inspection Check List
6-4 Power Supply Voltage and Ripple Limits
6-5 Maintenance Aids
6-6 2440 Troubleshooting Procedures
6-7 Video Option Troubleshooting
6-8 INIT PANEL States.....
6-3
6-5
6-6
6-10
6-13
6-37
6-104
6-108
V

2440 Service
OPERATORS SAFETY SUMMARY
Thegenera! safety information in this part of the summary is for both operating and
Specific warnings and cautions will be found throughout the manuai where they apply and
summary.
servicing personnel,
do not appear in this
Terms in This Manuai
CAUTION statements identify conditions or practices that
could result in damage to the equipment or other property.
WARNING statements identify conditions or practices that
could result in personal injury or loss of life.
Terms as Marked on Equipment
CAUTION indicates apersonal injury hazard not immedi-
ately accessible as one reads the markings, or ahazard to
property, including the equipment itself.
DANGER indicates apersonal injury hazard immediately
accessible as one reads the marking.
Grounding the Product
This product is grounded through the grounding conductor
of the power cord. To avoid electrical shock, plug the
power cord into aproperly wired receptacle before making
any connections to the product^ input or output terminals.
Aprotective ground connection by way of the grounding
conductor in the power cord is essential for safe operation.
Danger Arising from Loss of Ground
Upon loss of the protective-ground connection, all accessi-
ble conductive parts (including knobs and controls that
may appear to be insulated) can render an electric shock.
Symbols in This Manual
This symbol indicates where applicable cau-
tionary or other information is to be found. For
maximum input voltage see Table 1-1.
Use the Proper Power Cord
Use only the power cord and connector specified for the
instrument.
Symbols as Marked on Equipment
ff DANGER —High voltage.
Protective gound (earth) terminal.
Use the Proper Fuse .
To avoid fire hazard, use only the fuse specified in the
instrument parts list. Areplacement fuse must meet the
type, voltage rating, and current rating specifications for
the fuse that it replaces.
A\ ATTENTION —Refer to manual.
Power Source
This product is intended to operate from apower source
that will not apply more than 250 volts rms between the
supply conductors or between either supply conductor and
ground. Aprotective ground connection by way of the
grounding conductor in the power cord is essential for safe
operation.
Do Not Operate in Explosive Atmospheres
To avoid explosion, do not operate this instrument in an
atmosphere of explosive gasses.
Do Not Remove Covers or Panels
To avoid personal injury, the instrument covers or panels
should only be removed by qualified service personnel. Do
not operate the instrument without covers and panels
properly installed.
(I J
vi

2440 Service
SERVICING SAFETY SUMMARY
FOR QUALIFIED SERVICE PERSONNEL ONLY
Refer also to the preceding Operators Safety Summary.
Do Not Service Alone
Do not perform internal service or adjustment of this pro-
duct unless another person capable of rendering first aid
and resuscitation is present.
Use Care When Servicing With Power On
Dangerous voltages exist at several points in this product.
To avoid personal injury, do not touch exposed connec-
tions or components while power is on.
Disconnect power before removing protective panels, sol-
dering, or replacing components.
Power Source
This product is intended to operate from apower source
that does not apply more than 250 volts rms bwetween
the supply conductors or between either supply conductor
and ground. Aprotective ground connection by way of the
grounding connector in the power cord is essential for safe
operation.

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