Tektronix TBS2000 Series User manual

xx
TBS2000 Series
Digital Storage Oscilloscopes
ZZZ
Service Manual
*P077115000*
077-1150-00

TBS2000 Series
Digital Storage Oscilloscopes
ZZZ
Service Manual
xx
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 all safety summaries
before performing service.
www.tek.com
077-1150-00

Copyright © Tektronix. All rights reserved. Licensed software products are owned by Tektronix or its subsidiaries
or suppliers, and are protected by national copyright laws and international treaty provisions.
Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication
supersedes that in all previously published material. Specifications and price change privileges reserved.
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
Important safety information..................................................................................... iv
General safety summary ..................................................................................... iv
Service safety summary..................................................................................... vii
Terms in this manual ........................................................................................ vii
Symbols and terms on the product......................................................................... viii
Preface.............................................................................................................. ix
Manual conventions .......................................................................................... ix
Operating information
Operating information............................................................................................ 1-1
Theory of operation
Theory of operation .............................................................................................. 2-1
Power supply................................................................................................. 2-2
Front End assembly (4 channel models) .................................................................. 2-2
Main board ................................................................................................... 2-2
I/O board (4 channel models)............................................................................... 2-3
Front-panel board............................................................................................ 2-3
Adjustments
Adjustments....................................................................................................... 3-1
Maintenance
Maintenance....................................................................................................... 4-1
Preventing ESD.............................................................................................. 4-1
Inspection and cleaning ..................................................................................... 4-1
Module removal.............................................................................................. 4-5
Troubleshooting.............................................................................................. 4-5
Troubleshooting procedure ................................................................................. 4-6
Unpacking and repacking instructions .................................................................. 4-10
Replaceable parts list
Replaceable parts list............................................................................................. 5-1
Parts ordering information.................................................................................. 5-1
Using the replaceable parts list............................................................................. 5-2
The replaceable parts list.................................................................................... 5-3
TBS2000 Series Service Manual i

Table of Contents
List of Figures
Figure 2-1: TBS2000 block diagram (2 channel)............................................................. 2-1
Figure 2-2: TBS2000 block diagram (4 channel)............................................................. 2-1
Figure 4-1: Primary troubleshooting procedure flowchart................................................... 4-7
Figure 4-2: AC Power Supply module troubleshooting...................................................... 4-8
Figure 4-3: Board isolation troubleshooting flowchart....................................................... 4-9
Figure 5-1: Four channel models; front half................................................................... 5-3
Figure 5-2: Four channel models; rear half.................................................................... 5-5
Figure 5-3: Two channel models; front half................................................................... 5-7
Figure 5-4: Two channel models; rear half .................................................................... 5-9
ii TBS2000 Series Service Manual

Table of Contents
List of Tables
Table 4-1: External inspection checklist....................................................................... 4-3
Table 4-2: Internal inspection checklist........................................................................ 4-4
Table 4-3: Most likely board to replace for failed diagnostics .............................................. 4-9
Table 5-1: Four-channel model parts: front panel, display, and front chassis ............................. 5-4
Table 5-2: Four-channel model parts: inputs, main board, power supply, I/O, rear chassis, rear cover 5-6
Table 5-3: Two channel model parts; front panel, labels, front panel, LCD, chassis ..................... 5-8
Table 5-4: Two channel model parts; power supply, main board, AC connector/filter, rear cover .... 5-10
TBS2000 Series Service Manual iii

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, additional information is provided at
the end of this section. (See page vii, Service 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.
Comply with local and national safety 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. Use only the power cord specified for this product and
certified for the country of use.
Ground the product. 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, make sure that the product is properly grounded.
Do not disable the power cord grounding connection.
Power disconnect. 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.
iv TBS2000 Series Service Manual

Important safety information
Connect and disconnect properly. 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 ratings
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.
Avoid exposed circuitry. Do not touch exposed connections and components
when power is present.
Do not operate with suspected failures. If you suspect that there is damage to this
product, have it inspected by qualified service personnel.
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.
Do not operate in wet/damp conditions. Be aware that condensation may occur if
a unit is moved from a cold to a warm environment.
Do not operate in an explosive atmosphere.
Keep product surfaces clean and dry. Remove the input signals before you clean
the product.
TBS2000 Series Service Manual v

Important safety information
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 environment. Always place the product in a location
convenient for viewing the display and indicators.
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 finger guards 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 properly. Connect the probe output to the measurement
product before connecting the probe to the circuit under test. 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.
Connect and disconnect properly. De-energize the circuit under test before
connecting or disconnecting a current probe.
Connect the probe reference lead to earth ground only.
Do not connect a current probe to any wire that carries voltages above the current
probe voltage rating.
vi TBS2000 Series Service Manual

Important safety information
Inspect the probe and accessories. Before each use, inspect probe and accessories
for damage (cuts, tears, or defects in the probe body, accessories, or cable jacket).
Do not use if damaged.
Servicesafetysummary
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 power on. Dangerous voltages or currents may exist
in this product. Disconnect power, remove battery (if applicable), 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 this 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.
TBS2000 Series Service Manual vii

Important safety information
Symbols and terms 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
betakentoavoidthem. (Thissymbolmayalsobeusedtorefertheuserto
ratings in the manual.)
The following symbol(s) may appear on the product:
viii TBS2000 Series Service Manual

Preface
This service manual provides information that you need to troubleshoot,
disassemble, and replace parts on the following Tektronix oscilloscopes:
Model Bandwidth Channels
TBS2072 70 MHz 2
TBS2102 100 MHz 2
TBS2074 70 MHz 4
TBS2104 100 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.
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.
TBS2000 Series Service Manual ix

Preface
xTBS2000 Series Service Manual

Operating information

Operating information
For information on installing and operating your oscilloscope, refer to the
TBS2000 Series Digital Storage Oscilloscopes User Manual (Tektronix part
number 077-1147-xx English; other languages available), which is downloadable
from the Tektronix Web site (www.tek.com/downloads).
TBS2000 Series Service Manual 1–1

Operating information
1–2 TBS2000 Series Service Manual

Theory of operation