Tektronix MDO4000 Series User manual

xx
MDO4000 Series
Mixed Domain Oscilloscopes
ZZZ
Service Manual
*P077058501*
077-0585-01

MDO4000 Series
Mixed Domain 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
prior to performing service.
www.tektronix.com
077-0585-01

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.tektronix.com to find contacts in your area.

Table of Contents
General safety summary .......................................................................................... iv
Preface............................................................................................................. vii
Manual Conventions......................................................................................... vii
Where to Find Operating Information............................................................................ 1
Theory of Operation................................................................................................ 3
Power Supply................................................................................................... 3
I/O Board ....................................................................................................... 3
Main Board and Analog Board............................................................................... 3
Front-Panel Board ............................................................................................. 4
Adjustments......................................................................................................... 7
Maintenance......................................................................................................... 9
Preventing ESD................................................................................................ 9
Inspection and Cleaning....................................................................................... 9
Module Removal.............................................................................................. 13
Troubleshooting............................................................................................... 15
Troubleshooting Procedure .................................................................................. 15
Unpacking and Repacking Instructions .................................................................... 19
Replaceable Parts List............................................................................................. 21
Parts Ordering Information .................................................................................. 21
Using the Replaceable Parts List............................................................................ 22
MDO4000 Series Mixed Domain Oscilloscopes Service Manual i

Table of Contents
List of Figures
Figure 1: MDO4000 Series block diagram...................................................................... 5
Figure 2: Removing tabs from the front protective cover..................................................... 13
Figure 3: Module locator ......................................................................................... 14
Figure 4: Primary troubleshooting procedure .................................................................. 16
Figure 5: AC power supply troubleshooting procedure....................................................... 17
Figure 6: Module isolation troubleshooting procedure........................................................ 18
Figure 7: Exploded view, Front Panel assembly............................................................... 24
Figure 8: Display, analog board, and main board assembly .................................................. 26
Figure 9: Rear chassis and connecting modules ............................................................... 28
Figure 10: External parts ......................................................................................... 29
Figure 11: Rear chassis, showing cables and connectors ..................................................... 30
Figure 12: Main board, showing cable and connectors ....................................................... 31
ii MDO4000 Series Mixed Domain Oscilloscopes Service Manual

Table of Contents
List of Tables
Table 1: External inspection checklist........................................................................... 11
Table 2: Internal inspection checklist ........................................................................... 12
Table 3: Parts list column descriptions.......................................................................... 22
Table 4: Replaceable parts – Front Panel assembly ........................................................... 23
Table 5: Replaceable parts – Display, Analog board, and Main board ...................................... 25
Table 6: Replaceable parts – Rear chassis and connecting modules ........................................ 27
Table 7: Replaceable parts – External parts .................................................................... 29
Table 8: Replaceable parts – cable and connectors, rear chassis............................................. 30
Table 9: Replaceable parts – Cable and Connectors, Main board............................................ 31
MDO4000 Series Mixed Domain Oscilloscopes Service Manual iii

General safety summary
General safetysummary
Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it.
To avoid potential hazards, use this product only as specified.
Only qualified personnel should perform service procedures.
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.
Connect and disconnect properly. Do not connect or disconnect probes or test
leads while they are connected to a voltage source.
Connect and disconnect properly. De-energize the circuit under test before
connecting or disconnecting the current probe.
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.
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.
Connect the probe reference lead to earth ground only.
Do not apply a potential to any terminal, including the common terminal, that
exceeds the maximum rating of that terminal.
Power disconnect. The power cord disconnects the product from the power source.
Donotblockthepowercord;itmustremain accessible to the user at all times.
Do not operate without covers. Do not operate this product with covers or panels
removed.
Do not operate with suspected failures. If you suspect that there is damage to this
product, have it inspected by qualified service personnel.
Avoid exposed circuitry. Do not touch exposed connections and components when
power is present.
Do not operate in wet/damp conditions.
Do not operate in an explosive atmosphere.
Keep product surfaces clean and dry.
Provide proper ventilation. Refer to the manual's installation instructions for details
on installing the product so it has proper ventilation.
iv MDO4000 Series Mixed Domain Oscilloscopes Service Manual

General safety summary
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.
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.
WARN ING indicates an injury hazard not immediately accessible as you
read the marking.
CAUTION indicates a hazard to property including the product.
The following symbol(s) may appear on the product:
MDO4000 Series Mixed Domain Oscilloscopes Service Manual v

General safety summary
vi MDO4000 Series Mixed Domain Oscilloscopes Service Manual

Preface
This service manual provides information that you need to troubleshoot,
disassemble, and replace parts on the following Tektronix oscilloscopes:
Model Bandwidth Analog channels RF frequency
MDO4104-6 1 GHz 46GHz
MDO4104-3 1 GHz 43GHz
MDO4054-6 500 MHz 4 6GHz
MDO4054-3 500 MHz 4 3GHz
MDO4034-3 350 MHz 4 3GHz
MDO4014-3 100 MHz 4 3GHz
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.
MDO4000 Series Mixed Domain Oscilloscopes Service Manual vii

Preface
viii MDO4000 Series Mixed Domain Oscilloscopes Service Manual

WheretoFindOperatingInformation
For information on installing and operating your oscilloscope, refer to the
Tektronix MDO4000 Series Mixed Domain Oscilloscopes User Manual, which
was provided with your oscilloscope. This manual is also available, in 11
languages, at www.tektronix.com/manuals.
MDO4000 Series Mixed Domain Oscilloscopes Service Manual 1

Where to Find Operating Information
2 MDO4000 Series Mixed Domain Oscilloscopes Service Manual

Theory of Operation
This chapter describes the electrical operation of the oscilloscope to the module
level. The block diagram shows the oscilloscope module interconnections. (See
Figure 1 on page 5.)
Power Supply
The Power Supply board converts AC line voltage to +12 V to power for all
internal circuits.
I/O Board
The I/O board contains USB ports, an Ethernet port (LAN), a VGA Video port, an
AUX OUT BNC connector, and an EXT REF IN BNC connector.
Main Board and Analog Board
The Main and Analog boards contain the following functions:
Acquisition System The Acquisition system begins with the analog signal path and ends with a
digitized signal in memory. The signal enters a channel input, and then passes
through an attenuator and preamplifier. The analog signal from each preamplifier
goes through a digitizer, and then into acquisition memory. The analog signal
from each preamplifier is also distributed to a trigger circuit.
All of the inputs (including RF) are routed to the Analog board. The analog
channels are amplified and attenuated through the front-end circuitry, and are
output to the Main board. The RF channel is the same except that the RF input
signal is routed through an attenuator and a mixer and down converted. The
analog board has a controller that is used as an I/O controller for the front-end
(Analog board).
Trigger System The Trigger system digitizes the analog signals from the preamplifiers and
routes the digitized signal to the Trigger ASIC. Advanced trigger functions are
enabled only when the appropriate application modules and supporting software
are installed.
Display System The Display system combines live waveform data from acquisition memory with
menus and text, and stores this information in display memory. It then uses this
data to refresh the XGA display module (LCD).
MDO4000 Series Mixed Domain Oscilloscopes Service Manual 3

Theory of Operation
Processor System The Processor system contains a 460EX Power PC microprocessor that controls
the entire instrument. The processor system also contains FLASH ROM, system
RAM, and interfaces to USB ports and the Ethernet port.
Power Converter The Main board converts the +12 V power to other voltages used for the analog
and digital circuitry throughout the system. The +5 V standby power is used
to keep the Front Panel powered up at all times that AC power is connected to
the unit.
Front-Panel Board
The Front Panel board contains a microprocessor that reads the front-panel buttons
and controls, sends this information to the processor system on the Main board,
and controls power to the Main board. The Front Panel board also generates
the probe compensation output signal, provides an interface to the application
modules, and controls power to the Main board.
4 MDO4000 Series Mixed Domain Oscilloscopes Service Manual

Theory of Operation
Figure 1: MDO4000 Series block diagram
MDO4000 Series Mixed Domain Oscilloscopes Service Manual 5

Theory of Operation
6 MDO4000 Series Mixed Domain Oscilloscopes Service Manual

Adjustments
Please return the instrument to Tektronix if adjustment is required. There are
no adjustment procedures (calibrations) that can be performed by the customer.
Calibrations can only be performed at a Tektronix service center and require the
use of traceable test equipment (signal sources and measuring equipment) to
verify the performance of the instrument.
To determine if adjustment is required, use the Performance Verification
procedure in the MDO4000 Series Mixed Domain Oscilloscopes Specifications
and Performance Verification manual, available at www.tektronix.com/manuals.
Adjustment is also required after instrument repair.
MDO4000 Series Mixed Domain Oscilloscopes Service Manual 7

Adjustments
8 MDO4000 Series Mixed Domain Oscilloscopes Service Manual