Tektronix 2440 User manual

Service Manual
Tektronix
/
2440
Oscilloscope
Serial Number B014064 below
070-6603-00
Warning
The servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not
perform any servicing unless you are qualified to
do so. Refer to the Safety Summary prior to
performing service.
Please check for change information at the rear
of this manual.
First rinting: July 1988
Revised rinting: July 1993

Instrument Serial Numbers
Each instrument manufactured by Tektronix has a serial number on a panel insert or tag, or stamped on the
chassis. The first letter in the serial number designates the country of manufacture. The last fi e digits of the
serial number are assigned sequentially and are unique to each instrument. Those manufactured in the
United States ha e six unique digits. The country of manufacture is identified as follows:
BO10000
E200000
J300000
H700000
Tektronix, Inc., Bea erton, Oregon, USA
Tektronix United Kingdom, Ltd., London
Sony/Tektronix, Japan
Tektronix Holland, NV, Heeren een, The Netherlands
Instruments manufactured for Tektronix by external endors outside the United States are assigned a two digit
alpha code to identify the country of manufacture (e.g., JP for Japan, HK for Hong Kong, IL for Israel, etc.).
Tektronix, Inc., P.O. Box 500, Bea erton, OR 97077
Printed in U.S.A.
Copyright © Tektronix, Inc., 1988. All rights reser ed. Tektronix products are co ered by U.S. and foreign
patents, issued and pending. The following are registered trademarks: TEKTRONIX, TEK, TEKPROBE, and
SCOPE-MOBILE.

WARRANTY
Tektronix warrants that this product will be free from defects in materials and workmanship for a period of three (3) years from
the date of shipment. If any such product pro es defecti e during this warranty period, Tektronix, at its option, either will repair
the defecti e product without charge for parts and labor, or will pro ide a replacement in exchange for the defecti e product.
In order to obtain ser ice under this warranty, Customer must notify Tektronix of the defect before the expiration of the warranty
period and make suitable arrangements for the performance of ser ice. Customer shall be responsible for packaging and
shipping the defecti e product to the ser ice center designated by Tektronix, with shipping charges prepaid. Tektronixshall
pay for the return of the product to Customer if the shipment is to a location within the country in which the Tektronixser ice
center is located. Customer shall be responsible for paying all shipping charges, duties, taxes, and any other charges for
products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate maintenance
and care. Tektronix shall not be obligated to furnish ser ice under this warranty a) to repair damage resulting from attempts by
personnel other than Tektronix representati es to install, repair or ser ice the product; b) to repair damage resulting from
improper use or connection to incompatible equipment; or c) to ser ice a product that has been modified or integrated with
other products when the effect of such modification or integration increases the time or difficulty of ser icing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THIS PRODUCT IN LIEU OF ANY OTHER
WARRANTIES, EXPRESSED OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIESOF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. TEKTRONIX’ RESPONSIBILITY TO REPAIR OR
REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR
BREACH OF THIS WARRANTY TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS
ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.

2440 Ser ice
TABLE OF CONTENTS
Page
LIST OF ILLUSTRATIONS................................................ iii
LIST OF TABLES................................................................
OPERATORS SAFETY SUMMARY ................................ i
SERVICING SAFETY SUMMARY ................................... ii
Section 1 SPECIFICATION
INTRODUCTION ....................................... 1-1
PERFORMANCE CONDITIONS .......... 1-4
Section 2 PREPARATION 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 3 THEORY 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 C R T ................................. 3-75
SYSTEM I/O ............................................... 3-80
VIDEO OPTION ........................................ 3-84
LOW VOLTAGE POWER SUPPLY ..... 3-92
LOW VOLTAGE REGULATORS ......... 3-98
Section 4 PERFORMANCE 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 Ser ice
TABLE OF CONTENTS (cont)
Page
Section 5 ADJUSTMENT PROCEDURE
INTRODUCTION.............................................. 5-1
CALIBRATION SEQUENCE AND
PARTIAL PROCEDURES ........................ 5-1
WARM-UP TIME REQUIREMENT ...... 5-1
PRESERVATION OF
INSTRUMENT
CALIBRATION............................................. 5-2
INTERNAL ADJUSTMENTS.......................... 5-3
SELF CALIBRATION..................................... 5-19
EXTERNAL CALIBRATION ......................... 5-20
Section 6 MAINTENANCE
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
Page
DIAGNOSTICS AND
INTERNAL CALIBRATION
ROUTINES...................................................... 6-25
INTRODUCTION ....................................... 6-25
OVERVIEW ................................................ 6-25
CALIBRATION ROUTINES.................... 6-25
DIAGNOSTIC ROUTINES ...................... 6-27
DIAGNOSTICS OPERATION
VIA THE GPIB INTERFACE .................. 6-34
DIAGNOSTIC PROCEDURES .............. 6-35
Section 7 OPTIONS AND ACCESSORIES
OPTIONS DESCRIPTION ...................... 7-1
OPTIONS A1-A5— INTERNATIONAL
POWER CORDS ...................................... 7-1
OPTION 1R— RACKMOUNTED
2440............................................................. 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
RAtKMOUNTING ACCESSORIES ..... 7-2
OPTIONAL ACCESSORIES................... 7-2
Section 8 REPLACEABLE ELECTRICAL PARTS
Section 9 DIAGRAMS
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 Ser ice
LIST OF ILLUSTRATIONS
Figure Page
The 2440 Digital Oscilloscope.................................................................................................................. iii
1- 1 Dimensional drawing................................................................................................................................... 1-24
2- 1 LINE VOLTAGE SELECTOR, line fuse, and power cord receptacle ............................................... 2-1
3- 1 2440 simplified block diagram.................................................................................................................... 3-3
3-2 Simplified Memory Map of the 2440........................................................................................................ 3-18
3-3 System Clock wa eforms............................................................................................................................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 wa eforms........................................................................................................................ 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 wa eforms...............................................................................................................................3-87
3-14 Video Option field-sync identification....................................................................................................... 3-88
3-15 PWM Regulator and In erter.......................................................................................................................3-94
3-16 PWM switching wa eforms.......................................................................................................................... 3-96
5-1 Adjustment locations for Displays 4 through 6 ..................................................................................... 5-4
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 & Abo e) CH 1 and CH 2 CCD Clock Adjustments
(shown centered, as after doing part b)................................................................................................ 5-7
5-4 (SN B010249 & Below) CH 1 and CH 2 CCD 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 1 before L-clock adjustment............................................................................. 5-12
5-7 Sides 1 and 3 before adjustment of LIS and after .............................................................................. 5-13
5-8 CH 1 with L-clocks correctly adjusted, but with stray samples ........................................................ 5-14
5-9 Display for adjusting CCD A and T clocks............................................................................................. 5-15
5-10 Typical CH 1 and CH 2 displays after clock adjustment.................................................................... 5-16
5-11 Checking sample dispersion...................................................................................................................... 5-17
5- 12 Input and output (after adjustment) wa eforms.................................................................................... 5-20
6- 1 Multipin connector........................................................................................................................................ 6-8
6-2 Circuit board Location.................................................................................................................................. 6-16
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 wa eforms................................................................................................................................... 6-41
REV SEP 1988 ®

2440 Ser ice
LIST OF ILLUSTRATIONS (cont)
Page
6-8
6-9
6-10
Typical Register test wa eforms.............................................................................................................6-55
Front Panel n P diagnostics test...............................................................................................................6-79
System ftP data bit D7 in the Bus Isolate mode.................................................................................6-102
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
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.
A ll— Timebase/Display Board.
A17— High Voltage Board.
A16— Low Voltage Power Supply Board.
i

2440 Ser ice
LIST OF TABLES
Table Page
1-1 Electrical Characteristics......................................................................................................................... 1-5
1-2 En ironmental Characteristics................................................................................................................ 1-19
1-3 Mechanical Characteristics..................................................................................................................... 1-21
1- 4 Option 05 (TV Trigger) Electrical Characteristics............................................................................... 1-22
2- 1 Voltage, Fuse, and Power-Cord Data.................................................................................................. 2-2
3- 1 Host Memory-Mapped I/O....................................................................................................................... 3-20
3-2 Processor Control Register Functions................................................................................................. 3-21
3-3 Processor Miscellaneous Register (PMREG) Output Functions..................................................... 3-22
3-4 Wa eform ^P Address Decoding........................................................................................................... 3-27
3-5 Trigger Logic Array Addresses (6080h-6087h).................................................................................. 3-52
3-6 Phase Clock Array Control Lines (CC3 through CCO)...................................................................... 3-55
3-7 Holdoff Delay Range for Current Source s Charging Capacitor
Combinations............................................................................................................................................ 3-59
3- 8 Side Board Address Decoding............................................................................................................... 3-60
4- 1 Test Equipment Required........................................................................................................................ 4-2
4-2 Accuracy Limits CH 1 and CH 2 CURSOR VOLTS Readout and A and
B TRIGGER LEVEL Readouts.............................................................................................................. 4-10
4-3 Minimum Display Le el for CH 1 or CH 2 Triggering....................................................................... 4-19
4-4 Minimum Signal Le el for EXT1 or EXT2 Triggering ........................................................................ 4-21
6-1 Relati e Susceptibility to Static-Discharge Damage ......................................................................... 6-3
6-2 External Inspection Check List............................................................................................................... 6-5
6-3 Internal Inspection Check List................................................................................................................ 6-6
6-4 Power Supply Voltage and Ripple Limits............................................................................................. 6-10
6-5 Maintenance Aids...................................................................................................................................... 6-13
6-6 2440 Troubleshooting Procedures......................................................................................................... 6-37
6-7 Video Option Troubleshooting................................................................................................................ 6-104
6-8 INIT PANEL States.................................................................................................................................... 6-108
V

OPERATORS SAFETY SUMMARY
2440 Ser ice
The general safety information in this part of the summary is for both operating and servicing personnel.
Specific warnings and cautions will be found throughout the manual where they apply and do not appear in this
summary.
Terms in This Manual
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 a personal injury hazard not immedi
ately accessible as one reads the markings, or a hazard to
property, including the equipment itself.
DANGER indicates a personal 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 a oid electrical shock, plug the
power cord into a properly wired receptacle before making
any connections to the product input or output terminals.
A protecti e 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 protecti e-ground connection, all accessi
ble conducti e parts (including knobs and controls that
may appear to be insulated) can render an electric shock.
in This Manual
This symbol indicates where applicable cau
tionary or other information is to be found. For
maximum input oltage see Table 1-1.
as Marked on Equipment
DANGER — High oltage.
Protecti e gound (earth) terminal.
ATTENTION — Refer to manual.
Power Source
This product is intended to operate from a power source
that will not apply more than 250 olts rms between the
supply conductors or between either supply conductor and
ground. A protecti e ground connection by way of the
grounding conductor in the power cord is essential for safe
operation.
Symbols
A
Symbols
♦
©
A
Use the Proper Power Cord
Use only the power cord and connector specified for the
instrument.
Use the Proper Fuse
To a oid fire hazard, use only the fuse specified in the
instrument parts list. A replacement fuse must meet the
type, oltage rating, and current rating specifications for
the fuse that it replaces.
Do Not Operate in Explosi e Atmospheres
To a oid explosion, do not operate this instrument in an
atmosphere of explosi e gasses.
Do Not Remo e Co ers or Panels
To a oid personal injury, the instrument co ers or panels
should only be remo ed by qualified ser ice personnel. Do
not operate the instrument without co ers and panels
properly installed.
i