Tektronix TBS2072B, TBS2102B, TBS2202B, TBS2074B, TBS2104B Service Manual

TBS2000B Series

Digital Storage Oscilloscopes

Service Manual

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TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

Contacting Tektronix

Tektronix, Inc.

14150 SW Karl Braun Drive

P.O. Box 500

Beaverton, OR 97077

USA

For product information, sales, service, and technical support:

•In North America, call 1-800-833-9200.

•Worldwide, visit www.tek.com to find contacts in your area.

Table of Contents

Table of Contents
List of Figures................................................................................................................................................................................	5
List of Tables.................................................................................................................................................................................	6
Important safety information..........................................................................................................................................................	7
General safety summary........................................................................................................................................................	7
Service safety summary.........................................................................................................................................................	9
Terms in the manual...............................................................................................................................................................	9
Symbols on the product.........................................................................................................................................................	9
Preface........................................................................................................................................................................................	10
Manual conventions.............................................................................................................................................................	10
Modules........................................................................................................................................................................	10
Replaceable parts.........................................................................................................................................................	10
Safety............................................................................................................................................................................	10
Ordering information....................................................................................................................................................................	11
Theory of operation.....................................................................................................................................................................	12
Power supply.......................................................................................................................................................................	13
Front End assembly (4 channel models).............................................................................................................................	13
Main board...........................................................................................................................................................................	13
I/O board (4 channel models)..............................................................................................................................................	14
Front-panel board................................................................................................................................................................	14
Adjustments................................................................................................................................................................................	15
Adjustments.........................................................................................................................................................................	15
Maintenance................................................................................................................................................................................	16
Preventing ESD...................................................................................................................................................................	16
Inspection and cleaning.......................................................................................................................................................	16
General care.................................................................................................................................................................	16
Flat panel display cleaning...........................................................................................................................................	16
Exterior cleaning...........................................................................................................................................................	17
Interior cleaning............................................................................................................................................................	17
Lubrication....................................................................................................................................................................	18
Module removal...................................................................................................................................................................	18
Required tools and equipment......................................................................................................................................	18
To remove modules......................................................................................................................................................	19
Troubleshooting...................................................................................................................................................................	19
Adjustment after repair..................................................................................................................................................	19
Required tools and equipment......................................................................................................................................	19
Troubleshooting procedure..................................................................................................................................................	19
Primary troubleshooting flowchart.................................................................................................................................	20
AC Power Supply module troubleshooting flowchart....................................................................................................	21
Board isolation troubleshooting flowchart.....................................................................................................................	22
Unpacking and repacking instructions.................................................................................................................................	22
Unpacking.....................................................................................................................................................................	22
Repacking.....................................................................................................................................................................	23
Storage.........................................................................................................................................................................	23
Replaceable parts.......................................................................................................................................................................	24

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	Table of Contents
Parts ordering information....................................................................................................................................................	24
Part number revision level............................................................................................................................................	24
Module servicing...........................................................................................................................................................	24
Using the replaceable parts list............................................................................................................................................	24
Abbreviations................................................................................................................................................................	25
Exploded view...............................................................................................................................................................	25
The replaceable parts list.....................................................................................................................................................	25

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List of Figures

List of Figures
Figure 1: TBS2000B block diagram (2 channel).........................................................................................................................	12
Figure 2: TBS2000B block diagram (4 channel).........................................................................................................................	13
Figure 3: Primary troubleshooting procedure flowchart..............................................................................................................	20
Figure 4: AC Power Supply module troubleshooting..................................................................................................................	21
Figure 5: Board isolation troubleshooting flowchart....................................................................................................................	22
Figure 6: Four channel models; front half...................................................................................................................................	25
Figure 7: Four channel models; rear half....................................................................................................................................	28
Figure 8: Two channel models; front half....................................................................................................................................	30
Figure 9: Two channel models; rear half.....................................................................................................................................	32

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List of Tables

List of Tables
Table 1: External inspection checklist.........................................................................................................................................	17
Table 2: Internal inspection checklist...........................................................................................................................................	18
Table 3: Parts list column descriptions........................................................................................................................................	25
Table 4: Four-channel model parts: front panel, display, and front chassis.................................................................................	26
Table 5: Four-channel model parts: inputs, main board, power supply, I/O, rear chassis, rear cover.........................................	28
Table 6: Two-channel model parts: front panel, display, and front chassis.................................................................................	30
Table 7: Two-channel model parts: power supply, main board, AC connector/filter, rear cover..................................................	32

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Important safety information

Important safety information

This manual contains information and warnings that must be followed by the user for safe operation and to keep the product in a safe condition.

To safely perform service on this product, see the Service safety summary that follows the General safety summary.

General safety summary

Use the product only as specified. Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it. Carefully read all instructions. Retain these instructions for future reference.

This product shall be used in accordance with local and national codes.

For correct and safe operation of the product, it is essential that you follow generally accepted safety procedures in addition to the safety precautions specified in this manual.

The product is designed to be used by trained personnel only.

Only qualified personnel who are aware of the hazards involved should remove the cover for repair, maintenance, or adjustment. Before use, always check the product with a known source to be sure it is operating correctly.

This product is not intended for detection of hazardous voltages.

Use personal protective equipment to prevent shock and arc blast injury where hazardous live conductors are exposed.

To avoid fire or personal injury

Use proper power cord Ground the product

Power disconnect

Power disconnect

Connect and disconnect properly

Use only the power cord specified for this product and certified for the country of use.

This product is grounded through the grounding conductor of the power cord. To avoid electric shock, the grounding conductor must be connected to earth ground. Before making connections to the input or output terminals of the product, ensure that the product is properly grounded. Do not disable the power cord grounding connection.

The power switch disconnects the product from the power source. See instructions for the location. Do not position the equipment so that it is difficult to disconnect the power switch; it must remain accessible to the user at all times to allow for quick disconnection if needed.

The power cord disconnects the product from the power source. See instructions for the location. Do not position the equipment so that it is difficult to operate the power cord; it must remain accessible to the user at all times to allow for quick disconnection if needed.

Do not connect or disconnect probes or test leads while they are connected to a voltage source.

Use only insulated voltage probes, test leads, and adapters supplied with the product, or indicated by Tektronix to be suitable for the product.

Observe all terminal ratings To avoid fire or shock hazard, observe all rating and markings on the product. Consult the product manual for further ratings information before making connections to the product. Do not exceed the Measurement Category (CAT) rating and voltage or current rating of the lowest rated individual component of a product, probe, or accessory. Use caution when using 1:1 test leads because the probe tip voltage is directly transmitted to the product.

Do not apply a potential to any terminal, including the common terminal, that exceeds the maximum rating of that terminal.

Do not float the common terminal above the rated voltage for that terminal.

Do not operate without covers Do not operate this product with covers or panels removed, or with the case open. Hazardous voltage exposure is possible.

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	Important safety information
Avoid exposed circuitry	Do not touch exposed connections and components when power is present.
Do not operate with suspected	If you suspect that there is damage to this product, have it inspected by qualified service personnel.
failures
	Disable the product if it is damaged. Do not use the product if it is damaged or operates incorrectly. If in
	doubt about safety of the product, turn it off and disconnect the power cord. Clearly mark the product to
	prevent its further operation.
	Before use, inspect voltage probes, test leads, and accessories for mechanical damage and replace when
	damaged. Do not use probes or test leads if they are damaged, if there is exposed metal, or if a wear
	indicator shows.
	Examine the exterior of the product before you use it. Look for cracks or missing pieces.
	Use only specified replacement parts.
Use proper fuse	Use only the fuse type and rating specified for this product.
Wear eye protection	Wear eye protection if exposure to high-intensity rays or laser radiation exists.
Do not operate in wet/damp	Be aware that condensation may occur if a unit is moved from a cold to a warm environment.
conditions
Do not operate in an explosive
atmosphere
Keep product surfaces clean	Remove the input signals before you clean the product.
and dry
Provide proper ventilation	Refer to the installation instructions in the manual for details on installing the product so it has proper
	ventilation.
	Slots and openings are provided for ventilation and should never be covered or otherwise obstructed. Do
	not push objects into any of the openings.
Provide a safe working	Always place the product in a location convenient for viewing the display and indicators.
environment

Probes and test leads

Before connecting probes or test leads, connect the power cord from the power connector to a properly grounded power outlet. Keep fingers behind the protective barrier, protective finger guard, or tactile indicator on the probes.

Remove all probes, test leads and accessories that are not in use.

Use only correct Measurement Category (CAT), voltage, temperature, altitude, and amperage rated probes, test leads, and adapters for any measurement.

Beware of high voltages	Understand the voltage ratings for the probe you are using and do not exceed those ratings. Two ratings are
	important to know and understand:
	• The maximum measurement voltage from the probe tip to the probe reference lead
	• The maximum floating voltage from the probe reference lead to earth ground
	These two voltage ratings depend on the probe and your application. Refer to the Specifications section of
	the manual for more information.
	Warning: To prevent electrical shock, do not exceed the maximum measurement or maximum
	floating voltage for the oscilloscope input BNC connector, probe tip, or probe reference lead.
Connect and disconnect	Connect the probe output to the measurement product before connecting the probe to the circuit under test.
properly	Connect the probe reference lead to the circuit under test before connecting the probe input. Disconnect the
	probe input and the probe reference lead from the circuit under test before disconnecting the probe from the
	measurement product.

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	Important safety information
Connect and disconnect	De-energize the circuit under test before connecting or disconnecting the current probe.
properly
	Connect the probe reference lead to earth ground only.
	Do not connect a current probe to any wire that carries voltages or frequencies above the current probe
	voltage rating.
Inspect the probe and	Before each use, inspect probe and accessories for damage (cuts, tears, or defects in the probe body,
accessories	accessories, or cable jacket). Do not use if damaged.

Service safety summary

The Service safety summary section contains additional information required to safely perform service on the product. Only qualified personnel should perform service procedures. Read this Service safety summary and the General safety summary before performing any service procedures.

To avoid electric shock	Do not touch exposed connections.
Do not service alone	Do not perform internal service or adjustments of this product unless another person capable of rendering
	first aid and resuscitation is present.
Disconnect power	To avoid electric shock, switch off the product power and disconnect the power cord from the mains power
	before removing any covers or panels, or opening the case for servicing.

Use care when servicing with Dangerous voltages or currents may exist in this product. Disconnect power, remove battery (if applicable),

power on	and disconnect test leads before removing protective panels, soldering, or replacing components.
Verify safety after repair	Always recheck ground continuity and mains dielectric strength after performing a repair.

Terms in the manual

These terms may appear in this manual:

Warning: Warning statements identify conditions or practices that could result in injury or loss of life.

CAUTION: Caution statements identify conditions or practices that could result in damage to this product or other property.

Symbols on the product

These terms may appear on the product:

•DANGER indicates an injury hazard immediately accessible as you read the marking.

•WARNING indicates an injury hazard not immediately accessible as you read the marking.

•CAUTION indicates a hazard to property including the product.

When this symbol is marked on the product, be sure to consult the manual to find out the nature of the potential hazards and any actions which have to be taken to avoid them. (This symbol may also be used to refer the user to ratings in the manual.)

The following symbols may appear on the product:

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Preface

Preface

This service manual provides information that you need to troubleshoot, disassemble, and replace parts on the following Tektronix oscilloscopes:

Model	Bandwidth	Channels
TBS2072B	70 MHz	2
TBS2102B	100 MHz	2
TBS2202B	200 MHz	2
TBS2074B	70 MHz	4
TBS2104B	100 MHz	4
TBS2204B	200 MHz	4

Manual conventions

This manual uses certain conventions that you should become familiar with before performing service.

Modules

Throughout this manual, any replaceable component, assembly, or part is referred to by the term module.

Replaceable parts

This manual refers to any field-replaceable assembly or mechanical part specifically by its name or generically as a replaceable part. In general, a replaceable part is any circuit board or assembly, (such as the hard disk drive), or a mechanical part, (such as the I/O port connectors), that is listed in the replaceable parts list that can be replaced in the field. (See The replaceable parts list on page 25.)

Safety

Symbols and terms related to safety appear in the General Safety Summary.

Information for service procedures appears in both the General Safety Summary and the Service Safety Summary.

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