Tektronix TBS2000B Series User manual

TBS2000B Series
Digital Storage Oscilloscopes
Service Manual
*P077153900*
077-1539-00

TBS2000B Series
Digital Storage Oscilloscopes
Service Manual
www.tek.com
077-1539-00
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 all safety summaries prior to performing service.

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.

Table of Contents
Important safety information .............................................................................................................. iii
General safety summary ................................................................................................................ iii
Service safety summary ................................................................................................................. vi
Terms in the manual ..................................................................................................................... vii
Symbols on the product ................................................................................................................ vii
Preface ................................................................................................................................................ ix
Manual conventions ....................................................................................................................... ix
Modules .................................................................................................................................... ix
Replaceable parts ...................................................................................................................... ix
Safety ........................................................................................................................................ ix
Ordering information
Ordering information ...................................................................................................................... 1
Theory of operation
Power supply .................................................................................................................................. 4
Front End assembly (4 channel models) ......................................................................................... 5
Main board ...................................................................................................................................... 5
I/O board (4 channel models) ......................................................................................................... 6
Front-panel board ........................................................................................................................... 6
Adjustments
Adjustments .................................................................................................................................... 7
Maintenance
Preventing ESD .............................................................................................................................. 9
Inspection and cleaning ................................................................................................................ 10
General care ............................................................................................................................. 10
Flat panel display cleaning ...................................................................................................... 10
Exterior cleaning ..................................................................................................................... 11
Interior cleaning ...................................................................................................................... 12
Lubrication .............................................................................................................................. 13
Module removal ............................................................................................................................ 13
Required tools and equipment ................................................................................................. 14
To remove modules ................................................................................................................. 14
TBS2000B Series Service Manual i

Troubleshooting ............................................................................................................................ 14
Adjustment after repair ............................................................................................................ 15
Required tools and equipment ................................................................................................. 15
Troubleshooting procedure ........................................................................................................... 15
Primary troubleshooting flowchart .......................................................................................... 16
AC Power Supply module troubleshooting flowchart ............................................................ 17
Board isolation troubleshooting flowchart .............................................................................. 18
Unpacking and repacking instructions ......................................................................................... 19
Unpacking ............................................................................................................................... 19
Repacking ................................................................................................................................ 19
Storage ..................................................................................................................................... 19
Replaceable parts
Parts ordering information ............................................................................................................ 21
Part number revision level ....................................................................................................... 21
Module servicing ..................................................................................................................... 22
Using the replaceable parts list ..................................................................................................... 22
Abbreviations .......................................................................................................................... 23
Exploded view ......................................................................................................................... 23
The replaceable parts list .............................................................................................................. 23
Table of Contents
ii TBS2000B Series Service Manual

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.
TBS2000B Series Service Manual iii

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, ensure that the product is properly grounded. Do not
disable the power cord grounding connection.
Power disconnect. 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.
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.
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 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.
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.
Important safety information
iv TBS2000B Series Service Manual

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 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.
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 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 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 the current probe.
Important safety information
TBS2000B Series Service Manual v

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 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.
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 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.
Important safety information
vi TBS2000B Series Service Manual