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Service Manual
TAS 455 & TAS 465
Analog Oscilloscopes
B020099 and Below
070-8524-02
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.
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 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:
B010000 Tektronix, Inc., Beaverton, Oregon, USA
E200000 Tektronix United Kingdom, Ltd., London
J300000 Sony/Tektronix, Japan
H700000 Tektronix Holland, NV, Heerenveen, The Netherlands
Instruments manufactured for Tektronix by external vendors 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 Box 500, Beaverton, OR 97077
.O.
Printed in U.S.A.
Copyright E Tektronix, Inc.,1993. All rights reserved. Tektronix products are covered 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 proves defective during this warranty period, Tektronix, at its option, either will repair
the defective product without charge for parts and labor, or will provide a replacement in exchange for the defective product.
In order to obtain service 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 service. Customer shall be responsible for packaging and
shipping the defective product to the service center designated by Tektronix, with shipping charges prepaid. Tektronix shall
pay for the return of the product to Customer if the shipment is to a location within the country in which the Tektronix service
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 service under this warranty a) to repair damage resulting from attempts by
personnel other than Tektronix representatives to install, repair or service the product; b) to repair damage resulting from
improper use or connection to incompatible equipment; or c) to service 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 servicing 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 WARRANTIES OF
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.
Table of Contents
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Symbols and Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Specific Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Related Manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xviii
Specifications
Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
User Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
AUTOSET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
General Purpose Knob and TOGGLE . . . . . . . . . . . . . . . . . . . . 12
Save/Recall Setups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Vertical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Horizontal System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Trigger System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Measurement Cursors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Nominal Traits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Warranted Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Performance Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Typical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 17
Operation
Installation and Power On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Quick Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Selecting and Deselecting Input Channels . . . . . . . . . . . . . . . . . 2 3
Using the Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3
Connecting a Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4
Using AUTOSET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4
Compensating the Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 5
Menu Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 8
TAS 455 and TAS 465 Service Manual i
Table of Contents
Theory of Operation
Circuit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Logic Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Module Interconnection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Analog Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Attenuators A1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Probe Coding Interface A1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Analog Acquisition Hybrid A1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
External Trigger A1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Processor System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Processor Subsystem A5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
ROM/RAM Subsystem A5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Readout Subsystem A5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Front Panel Interface Subsystem A5 . . . . . . . . . . . . . . . . . . . . . 35
Analog Board Interface Subsystem A5 . . . . . . . . . . . . . . . . . . . 35
Display Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Vertical Output A3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Horizontal Output A3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
High Voltage A3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Menu Switches A4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
CPU A4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
FPP Pots and Probes A4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
LEDs and Driver A4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Switches A4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Performance Verification
General Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Using the Brief Performance Checks Procedures . . . . . . . . . . . 41
Using the Performance Tests Procedures . . . . . . . . . . . . . . . . . . 41
Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Brief Performance Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Power On Self Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Functional Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Functional Tests Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Verify the Probe Compensator Output . . . . . . . . . . . . . . . . . . . 44
Verify the Input Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Verify the Alt/Chop and Add Functions . . . . . . . . . . . . . . . . . . . 46
Verify the Time Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Verify the Trigger System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Verify the External Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
ii Contents
Table of Contents
Temperature Compensation Calibrations . . . . . . . . . . . . . . . . . . 49
Horizontal Sweep Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Vertical Signal Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 11
Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 13
Performance Tests Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . 4 13
Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 13
Vertical System Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 15
Check DC Gain and Voltage Measurement Accuracy . . . . . . 4 15
Check Trigger Level Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . 4 16
Check DC Coupling Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . 4 17
Check X Axis Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 19
Horizontal System Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 19
Check Time Base and Time Cursor Accuracy . . . . . . . . . . . . . 4 19
Check Dual Delay Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 22
Trigger System Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 24
Check Trigger Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 24
Video Trigger Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 28
Adjustment
Adjustment Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Requirements for Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Access to Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Warm Up Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Performing the Adjustment Procedures . . . . . . . . . . . . . . . . . . . . 52
Complete Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Partial Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Adjustment Dependencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Adjustment Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Power Supply Adjustment
(New Style Power Supply) . . . . . . . . . . . . . . . . . . . . . . . . . . 54
CRT Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Low Frequency Output Compensation . . . . . . . . . . . . . . . . . . . 56
Factory Horizontal Cal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Factory Vertical Cal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 11
High Frequency Step Response . . . . . . . . . . . . . . . . . . . . . . . . . 5 14
Attenuator Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 16
Vertical Gain Adjust (Cabinet On) . . . . . . . . . . . . . . . . . . . . . . . . 5 17
TAS 455 and TAS 465 Service Manual iii
Table of Contents
Maintenance
Maintenance Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Before Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Tektronix Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Warranty Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Repair or Calibration Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Self Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Preventing ESD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Inspection and Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
General Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Inspection and Cleaning Procedures . . . . . . . . . . . . . . . . . . . . . . 65
Inspection Exterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Cleaning Procedure Exterior . . . . . . . . . . . . . . . . . . . . . . . . . 66
Cleaning Procedure Interior . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Cleaning the CRT Implosion Shield . . . . . . . . . . . . . . . . . . . . . . 67
Removal and Installation Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 69
Preparation Please Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Cable Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
General Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 10
Summary of Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 10
Line Cord and Line Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 14
Line Cord . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 14
Line Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 15
Front Panel Knobs and Shafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 15
Removing Front Panel Knobs and Shafts . . . . . . . . . . . . . . . . . 6 15
Installing Front Panel Knobs and Shafts . . . . . . . . . . . . . . . . . . 6 16
Feet, Rear Cover, and Cabinet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 17
Rear Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 18
Cabinet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 18
Replacing the Front Feet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 18
Front Panel Trim, Menu and Power Buttons . . . . . . . . . . . . . . . . 6 18
Removing the Front Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 18
Menu Buttons and Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 19
Power Button Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 19
Installing the Front Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 19
A62 Front Panel Module Removal . . . . . . . . . . . . . . . . . . . . . . . . . 6 20
Front Panel Module Disassembly/Assembly . . . . . . . . . . . . . . 6 21
Menu Flex Circuit Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 23
A1 Analog Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 24
Display Driver Board (A3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 26
CRT Implosion Shield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 27
Fan and Fan Mount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 29
Fan and Fan Mount Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 29
Fan and Fan Mount Installation . . . . . . . . . . . . . . . . . . . . . . . . . 6 31
iv Contents
Table of Contents
CRT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 31
CRT Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 31
CRT Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 33
CRT Light Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 34
CRT Front Bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 35
A2 Display Control Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 36
A63 Power Supply Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 37
Power Supply Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 37
Power Supply Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 38
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 41
Troubleshooting Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 41
Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 41
Symptom Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 42
Repackaging Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 51
Options
Options A1-A5: International Power Cords . . . . . . . . . . . . . . . 7 1
Warranty Plus Service Options . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1
Option 3R: Rackmount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1
Option 02: Front Cover and Pouch . . . . . . . . . . . . . . . . . . . . . . 7 2
Option 23: Additional Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2
Option 9C: Certificate of Calibration and Test Data Report . . 7 2
Replaceable Electrical Parts List
Diagrams
Diagrams and Circuit Board Illustrations . . . . . . . . . . . . . . . . . . . . . . 91
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1
Component Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1
Graphic Items and Special Symbols Used in This Manual . . . 9 1
Component Locator Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2
Replaceable Mechanical Parts List
TAS 455 and TAS 465 Service Manual v
Table of Contents
vi Contents
List of Figures
Figure 2 1: Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1
Figure 2 2: Fuse Compartment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2
Figure 2 3: POWER Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2
Figure 2 4: Probe Compensation Signal Displayed after AUTOSET . 2 5
Figure 2 5: Connections for Compensating a Probe . . . . . . . . . . . . . . 2 5
Figure 2 6: How Probe Compensation Affects Signals . . . . . . . . . . . . 2 7
Figure 2 7: Location of Probe Head Adjustment . . . . . . . . . . . . . . . . . . 2 7
Figure 2 8: Menu Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 8
Figure 3 1: Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Figure 4 1: Graticule References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Figure 4 2: Test Hookup for Functional Tests . . . . . . . . . . . . . . . . . . . . 44
Figure 4 3: Horizontal Adjustments (One) . . . . . . . . . . . . . . . . . . . . . . . 4 10
Figure 4 4: Horizontal Adjustments (Two) . . . . . . . . . . . . . . . . . . . . . . . 4 10
Figure 4 5: Horizontal Adjustments (Three) . . . . . . . . . . . . . . . . . . . . . . 4 11
Figure 4 6: Gain and Voltage Test Setup . . . . . . . . . . . . . . . . . . . . . . . . 4 15
Figure 4 7: Trigger Level Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 17
Figure 4 8: Bandwidth Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 18
Figure 4 9: X Axis Gain Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 19
Figure 4 10: Timing Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 20
Figure 4 11: Dual Delay Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 23
Figure 4 12: Trigger Sensitivity Test Setup (One) . . . . . . . . . . . . . . . . . 4 25
Figure 4 13: Trigger Sensitivity Test Setup (Two) . . . . . . . . . . . . . . . . . 4 26
Figure 4 14: Trigger Sensitivity Test Setup (Three) . . . . . . . . . . . . . . . . 4 27
Figure 4 15: Trigger Sensitivity Test Setup (Four) . . . . . . . . . . . . . . . . . 4 27
Figure 4 16: Video Trigger Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 29
Figure 5 1: Location of Boards for Adjustments . . . . . . . . . . . . . . . . . . 52
Figure 5 2: CRT Adjustments Calibration Setup . . . . . . . . . . . . . . . . . . 55
Figure 5 3: Low Frequency Output Compensation Calibration
Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Figure 5 4: Horizontal Adjustments (One) . . . . . . . . . . . . . . . . . . . . . . . 58
Figure 5 5: Horizontal Adjustments (Two) . . . . . . . . . . . . . . . . . . . . . . . 59
Figure 5 6: Horizontal Adjustments (Three) . . . . . . . . . . . . . . . . . . . . . . 59
Figure 5 7: Horizontal Output Calibration Setup . . . . . . . . . . . . . . . . . . 5 10
Figure 5 8: Factory Vertical Calibration Setup . . . . . . . . . . . . . . . . . . . . 5 12
Figure 5 9: External Trigger Calibration Setup . . . . . . . . . . . . . . . . . . . 5 13
Figure 5 10: Vertical Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 13
Figure 5 11: Adjusting Vertical Gain and Centering . . . . . . . . . . . . . . . 5 14
TAS 455 and TAS 465 Service Manual vii
List of Figures
Figure 5 12: High Frequency Step Response Test Setup . . . . . . . . . . 5 15
Figure 5 13: Attenuator Compensation Test Setup . . . . . . . . . . . . . . . . 5 16
Figure 5 14: Display Driver Board Adjustment Locations . . . . . . . . . . 5 19
Figure 5 15: Analog Board Adjustment Locations . . . . . . . . . . . . . . . . 5 20
Figure 5 16: Power Supply Adjustment Location
(New Power Supply) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 21
Figure 5 17: Location of J205 (CAL-DIS) on the CPU Board . . . . . . 5 22
Figure 6 1: Oscilloscope Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 10
Figure 6 2: Cabinet and Front Panel Mounted Modules . . . . . . . . . . . 6 12
Figure 6 3: Internal Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 13
Figure 6 4: Cables and Cable Routing . . . . . . . . . . . . . . . . . . . . . . . . . . 6 14
Figure 6 5: Line Fuse and Line Cord Removal . . . . . . . . . . . . . . . . . . . 6 15
Figure 6 6: Knob and Shaft Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 16
Figure 6 7: Rear Cover, Cabinet, and Feet Removal . . . . . . . . . . . . . . 6 17
Figure 6 8: Trim Ring and Menu Buttons Removal . . . . . . . . . . . . . . . . 6 20
Figure 6 9: A62 Front Panel Module Removal . . . . . . . . . . . . . . . . . . . . 6 21
Figure 6 10: Disassembly of Front Panel Assembly . . . . . . . . . . . . . . . 6 22
Figure 6 11: Front Panel Ground Spring . . . . . . . . . . . . . . . . . . . . . . . . 6 23
Figure 6 12: Menu Flex Circuit Board Removal . . . . . . . . . . . . . . . . . . . 6 24
Figure 6 13: A1 Analog Board Removal . . . . . . . . . . . . . . . . . . . . . . . . . 6 26
Figure 6 14: Location of Display Driver Board . . . . . . . . . . . . . . . . . . . . 6 27
Figure 6 15: CRT Implosion Shield Removal . . . . . . . . . . . . . . . . . . . . . 6 28
Figure 6 16: Fan Mount Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 30
Figure 6 17: Fan and Fan Mount Removal . . . . . . . . . . . . . . . . . . . . . . . 6 30
Figure 6 18: CRT Rear Bracket and Ground Wire . . . . . . . . . . . . . . . . . 6 32
Figure 6 19: CRT Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 34
Figure 6 20: Removing the CRT front bracket . . . . . . . . . . . . . . . . . . . . 6 36
Figure 6 21: Removing the Display Control Board . . . . . . . . . . . . . . . . 6 37
Figure 6 22: Power Button Shaft Disconnect . . . . . . . . . . . . . . . . . . . . . 6 38
Figure 6 23: Power Supply Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 39
Figure 6 24: A5 CPU Board Troubleshooting Procedure . . . . . . . . . . . 6 44
Figure 6 25: A1 Analog Board Troubleshooting Procedure . . . . . . . . 6 45
Figure 6 26: A3 Display Driver Board Troubleshooting Procedure . . 6 47
Figure 6 27: A62 Front Panel module Troubleshooting Procedure . . 6 49
Figure 6 28: A2 Display Control Board Troubleshooting Procedure . 6 50
Figure 9 1: Graphic Items and Special Symbols Used in This
Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Figure 9 2: Circuit Board Component Locator Diagram Key . . . . . . . 92
Figure 9 3: Semiconductor Lead Configurations . . . . . . . . . . . . . . . . . 93
Figure 9 4: Locating Components on Circuit Board or Schematic
Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
viii Contents
Figure 9 5: A1 Analog Board
TAS 455: SN B010100 and Above
TAS 465: SN B010100 to B012541 . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Figure 9 6: A1 Analog Board
TAS 465: SN B012542 and Above . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Figure 9 7: A2 Display Control Board . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 11
Figure 9 8: A3 Display Driver Board
TAS 455: SN B010100 and Above
TAS 465: SN B010100 to B012561 . . . . . . . . . . . . . . . . . . . . . . . . . . 9 13
Figure 9 9: A3 Display Driver Board
TAS 465: SN B012562 and Above . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 15
Figure 9 10: A4 Front Panel Board
TAS 455: SN B010100 and Above
TAS 465: SN B010100 to B012835 . . . . . . . . . . . . . . . . . . . . . . . . . . 9 17
Figure 9 11: A4 Front Panel Board
TAS 465: SN B012836 and Above . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 19
Figure 9 12: A5 Processor Board
TAS 455: SN B010100 to B011862
TAS 465: SN B010100 to B011621 . . . . . . . . . . . . . . . . . . . . . . . . . . 9 21
Figure 9 13: A5 Processor Board
TAS 455: SN B011863 and Above
TAS 465: SN B011622 to B013240 . . . . . . . . . . . . . . . . . . . . . . . . . . 9 23
Figure 9 14: A5 Processor Board
TAS 465: SN B013241 and Above . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 25
Figure 10 1: Cabinet and Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 5
Figure 10 2: Front Panel Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
Figure 10 3: Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 12
Figure 10 4: Circuit Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 14
Figure 10 5: Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 15
TAS 455 and TAS 465 Service Manual ix
List of Figures
x Contents
List of Tables
Table 1 1: Nominal Traits Vertical Deflection System . . . . . . . . . . . 1 5
Table 1 2: Nominal Traits Time Base System . . . . . . . . . . . . . . . . . . 1 6
Table 1 3: Nominal Traits Triggering System . . . . . . . . . . . . . . . . . . 1 6
Table 1 4: Nominal Traits Video Triggering System . . . . . . . . . . . . 1 6
Table 1 5: Nominal Traits Cursors . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 7
Table 1 6: Nominal Traits XY Operation . . . . . . . . . . . . . . . . . . . . . . 1 7
Table 1 7: Nominal Traits Setup Memory Characteristics . . . . . . . 1 7
Table 1 8: Nominal Traits Power Fuse . . . . . . . . . . . . . . . . . . . . . . . . 1 7
Table 1 9: Nominal Traits Mechanical . . . . . . . . . . . . . . . . . . . . . . . . 1 8
Table 1 10: Warranted Characteristics Vertical Deflection
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Table 1 11: Warranted Characteristics Time Base System . . . . . . 1 11
Table 1 12: Warranted Characteristics Triggering System . . . . . . 1 12
Table 1 13: Warranted Characteristics Video Triggering . . . . . . . . 1 13
Table 1 14: Warranted Characteristics Cursors . . . . . . . . . . . . . . . . 1 13
Table 1 15: Warranted Characteristics XY Operation . . . . . . . . . . . 1 14
Table 1 16: Warranted Characteristics Power Requirements . . . . 1 14
Table 1 17: Warranted Characteristics Environmental and Safety 1 14
Table 1 18: Typical Characteristics Vertical Deflection System . . . 1 17
Table 1 19: Typical Characteristics Time Base System . . . . . . . . . 1 17
Table 1 20: Typical Characteristics Triggering System . . . . . . . . . 1 18
Table 1 21: Typical Characteristics Video Triggering System . . . . 1 19
Table 1 22: Typical Characteristics Z Axis . . . . . . . . . . . . . . . . . . . . 1 19
Table 1 23: Typical Characteristics Probe Compensator . . . . . . . . 1 19
Table 1 24: Typical Characteristics Setup Memory . . . . . . . . . . . . . 1 20
Table 4 1: Required Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 14
Table 4 2: DC Gain and Delta Volts Accuracy . . . . . . . . . . . . . . . . . . . 4 16
Table 4 3: DC Coupled Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 18
Table 4 4: Time Base and Cursor Accuracies (Mag Off) . . . . . . . . . . . 4 20
Table 4 5: Time Base Accuracy (Mag On) . . . . . . . . . . . . . . . . . . . . . . . 4 22
Table 4 6: 500 ms Dual Delay Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . 4 24
Table 5 1: Adjustments and Dependencies . . . . . . . . . . . . . . . . . . . . . 53
TAS 455 and TAS 465 Service Manual xi
List of Tables
Table 6 1: Relative Susceptibility to Static Discharge Damage . . . . . 63
Table 6 2: External Inspection Check List . . . . . . . . . . . . . . . . . . . . . . . 66
Table 6 3: Tools Required for Module Removal . . . . . . . . . . . . . . . . . . 6 11
Table 6 4: Equipment Required for Troubleshooting . . . . . . . . . . . . . . 6 41
Table 6 5: Symptom Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 42
Table 7 1: International Power Cords . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
xii Contents
Safety Summary
Please take a moment to review these safety precautions. They are provided
for your protection and to prevent damage to the oscilloscope. This safety
information applies to all operators and service personnel.
Symbols and Terms These two terms appear in manuals:
H statements identify conditions or practices that could result in
damage to the equipment or other property.
H statements identify conditions or practices that could result in
personal injury or loss of life.
These two terms appear on equipment:
H CAUTION indicates a personal injury hazard not immediately accessible
as one reads the marking, or a hazard to property including the equip
ment itself.
H DANGER indicates a personal injury hazard immediately accessible as
one reads the marking.
This symbol appears in manuals:
Static Sensitive Devices
These symbols appear on equipment:
DANGER Protective ATTENTION
High Voltage ground (earth) Refer to
terminal manual
TAS 455 and TAS 465 Service Manual xiii
Safety Summary
Specific Precautions Observe all of the following precautions to ensure your personal safety and
to prevent damage to either the TAS 455 and TAS 465 Analog Oscilloscopes
or equipment connected to them.
Do Not Perform Service While Alone
Do not perform internal service or adjustment of this product 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 connections or components while power is on.
Disconnect power before removing protective panels, soldering, or replacing
components.
Power Source
The TAS 455 and TAS 465 Analog Oscilloscopes are intended to operate
from a power source that will not apply more than 250 VRMS between the
supply conductors or between either supply conductor and ground. A pro
tective ground connection, through the grounding conductor in the power
cord, is essential for safe system operation.
Grounding the Oscilloscope
The TAS 455 and TAS 465 Analog Oscilloscopes are grounded through the
power cord. To avoid electric shock, plug the power cord into a properly
wired receptacle where earth ground has been verified by a qualified service
person. Do this before making connections to the input or output terminals of
the oscilloscope.
Without the protective ground connection, all parts of the TAS 455 and
TAS 465 Analog Oscilloscopes are potential shock hazards. This includes
knobs and controls that may appear to be insulators.
Use the Proper Power Cord
Use only the power cord and connector specified for your product. Use only
a power cord that is in good condition.
Use the Proper Fuse
To avoid fire hazard, use only the fuse specified in the parts list for your
product. It must be identical in type, voltage rating, and current rating.
xiv Safety
Safety Summary
Do Not Remove Covers or Panels
To avoid personal injury, do not operate the TAS 455 or TAS 465 Oscillo
scope without the panels or covers.
Do Not Operate in Explosive Atmospheres
The TAS 455 or TAS 465 Oscilloscope provide no explosion protection from
static discharges or arcing components. Do not operate the TAS 455 or
TAS 465 Oscilloscope in an atmosphere of explosive gasses.
Electric Overload
Never apply a voltage to a connector on the TAS 455 or TAS 465 Oscillo
scope that is outside the range specified for that connector.
TAS 455 and TAS 465 Service Manual xv
Safety Summary
xvi Safety
Preface
This is the Service Manual for the TAS 455 and TAS 465 Analog Oscillo
scopes. This manual provides you with both service and limited operation
information.
Use the Introduction section to learn what the TAS 455 and TAS 465 Analog
Oscilloscopes can do and about the available options and accessories.
Use the Operation section to learn about applying power. This section also
contains brief examples of how to use the controls.
Use the Specifications section as a reference for all nominal, warranted, and
typical characteristics for the TAS 455 and TAS 465 Analog Oscilloscopes.
Use the Theory section to help you understand the operation of the oscillo
scope to the block level.
Use the Performance Verification section to verify the functionality and war
ranted characteristics of the oscilloscope.
Use the Adjustment section to bring the TAS 455 and TAS 465 Analog Oscil
loscopes into conformance with the warranted characteristics listed in the
Specifications section. You should adjust the oscilloscope if indicated by the
Performance Verification procedures.
Use the Maintenance section to learn how to perform general maintenance
of your product. Procedures to disassemble and troubleshoot the oscillo
scope are also located in this section.
Use the Replaceable Electrical Parts List section for a list of the electrical
parts.
Use the Diagrams section for troubleshooting the oscilloscope. This section
contains board dollies, block diagrams and schematics for each board.
Use the Replaceable Mechanical Parts List section for a list of the mechani
cal parts.
TAS 455 and TAS 465 Service Manual xvii
Preface
Related Manuals Other documentation for the TAS 455 and TAS 465 Analog Oscilloscopes
include:
H The Reference (Tektronix part number 070 8522 XX) gives you a quick
overview of how to operate your TAS 400 Series Analog Oscilloscopes.
H The Instruction manual (Tektronix part number 070 8523 XX) contains
detailed operating information and limited service information.
H The XYZs of Analog and Digital Oscilloscopes (Tektronix part number
070 8690 XX) provides you with a basic understanding of oscilloscopes
and their use.
xviii Preface
Product Description
Your Tektronix TAS 455 and TAS 465 Analog Oscilloscopes are superb
tools for processing and displaying electrical signals. Their performance
addresses the needs of both benchtop and portable applications with the
following features:
H 60 MHz minimum bandwidth (TAS 455)
100 MHz minimum bandwidth (TAS 465)
H Two channel input
H Complete cursor measurement system
H Voltage
H Time
H Frequency
H Delayed time base
H AUTOSET feature
H Front panel setup memory
H External trigger input
TAS 455 and TAS 465 Service Manual 11
Product Description
The features of the TAS 455 and TAS 465 Analog Oscilloscopes are briefly
described here to help get you acquainted with the operating systems.
User Interface This oscilloscope uses a combination of front panel buttons, knobs, and
on screen menus to control its many functions. The front panel controls are
grouped according to function: vertical, horizontal, trigger, and special.
Within each group, any function adjusted often, such as vertical positioning
or the time base setting, is set directly by its own front panel control.
AUTOSET
The AUTOSET button provides you with a usable, triggered display of a
signal applied to an input channel. Many instrument controls and menus are
set to a pre defined state, providing you with a known starting point for your
measurements.
Menus
Those functions for which control settings changed less often, such as
vertical coupling and trigger mode, are set indirectly. That is, pressing a
front panel button, such as VERTICAL MENU, displays a menu of functions
at the bottom of the screen related to that button. (For the button VERTICAL
MENU, the menu displayed contains functions such as coupling and band
width.) The buttons below this main menu select a function, such as cou
pling and displays a sub menu of settings for that function, such as DC, AC,
or GND, at the right side of the screen. The buttons to the right of the menu
select a setting, such as DC.
General Purpose Knob and TOGGLE
Some menus assign the General Purpose Knob to a selected adjustment.
The method employed is the same as for selecting a function, except the
final selection in the side menu causes the General Purpose Knob to adjust
some function, such as the position of measurement cursors on screen.
Pressing the CLEAR MENU button clears the assignment of the General
Purpose Knob except when assigned to adjust cursors or delay time.
The TOGGLE button works in conjunction with the General Purpose Knob
when positioning cursors. Each press of the TOGGLE button switches
which cursor is active, and therefore controlled by the General Purpose
Knob.
Save/Recall Setups
You can store up to four complete front panel setups in memory. Once you
complete a complex setup and then save it in one of the four memory loca
tions, you can retrieve it at any time. Saved front panel settings do not
include the assignment of the General Purpose Knob.
12 Specifications
P