Tektronix 784A - Manuals - manualsarea.com

Page 3 - WARRANTY

WARRANTY Tektronix warrants that this product will be free from defects in materials and workmanship for a period of three (3) yearsfrom the date of shipment. If any such product proves defective during this warranty period, Tektronix, at its option, eitherwill repair the defective product without c...

Page 5 - Table of Contents; Specifications

TDS 684A, TDS 744A, & TDS 784A Service Manual i Table of Contents General Safety Summary ix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Safety Summary xiii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface xv . . . . . . . . . ....

Page 6 - ii; Adjustment Procedures; Removal and Installation Procedures

Table of Contents ii TDS 684A, TDS 744A, & TDS 784A Service Manual Performance Tests 4–15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Prerequisites 4–15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

Page 7 - iii; List of Figures

Table of Contents TDS 684A, TDS 744A, & TDS 784A Service Manual iii List of Figures Figure 2–1: Map of Display Functions 2–8 . . . . . . . . . . . . . . . . . . . . . . . . . Figure 4–1: Map of Display Functions 4–3 . . . . . . . . . . . . . . . . . . . . . . . . . Figure 4–2: Verifying Adjustme...

Page 8 - iv

Table of Contents iv TDS 684A, TDS 744A, & TDS 784A Service Manual Figure 4–31: 60 Hz Rejection Test Setup Signal 4–72 . . . . . . . . . . . . . . . . . . Figure 4–32: Subsequent 60 Hz Rejection Test Hookup 4–73 . . . . . . . . . . . Figure 4–33: 60 Hz Rejection Test Result – TDS 684A Shown 4–74...

Page 11 - vii; List of Tables

Table of Contents TDS 684A, TDS 744A, & TDS 784A Service Manual vii List of Tables Table 1–1: Key Features of the TDS 684A and 7XXA Oscilloscopes 1–1 Table 1–2: Record Length vs. Divisions per Record, Samples per Division and Sec/Div Sequence 1–3 . . . . . . . . . . . . . . . . . . . . . . . . ....

Page 12 - viii

Table of Contents viii TDS 684A, TDS 744A, & TDS 784A Service Manual Table 6–2: External Inspection Check List 6–5 . . . . . . . . . . . . . . . . . . . . . Table 6–3: Internal Inspection Check List 6–6 . . . . . . . . . . . . . . . . . . . . . . Table 6–4: Tools Required for Module Removal 6–11...

Page 13 - ix; General Safety Summary; Only qualified personnel should perform service procedures.; Injury Precautions

TDS 684A, TDS 744A, & TDS 784A Service Manual ix General Safety Summary Review the following safety precautions to avoid injury and prevent damage tothis product or any products connected to it. Only qualified personnel should perform service procedures. Injury Precautions To avoid fire hazard, ...

Page 14 - Safety Terms and Symbols; These terms may appear in this manual:

General Safety Summary x TDS 684A, TDS 744A, & TDS 784A Service Manual Before applying power, ensure that the line selector is in the proper position forthe power source being used. To prevent product overheating, provide proper ventilation. If you suspect there is damage to this product, have i...

Page 15 - xi; The following symbols may appear on the product:; Certifications and Compliances; Symbols on the Product

General Safety Summary TDS 684A, TDS 744A, & TDS 784A Service Manual xi The following symbols may appear on the product: DANGER High Voltage Protective Ground (Earth) Terminal ATTENTION Refer to Manual Double Insulated Certifications and Compliances CSA Certification includes the products and po...

Page 16 - xii

General Safety Summary xii TDS 684A, TDS 744A, & TDS 784A Service Manual

Page 17 - xiii; Service Safety Summary; To avoid electric shock, do not touch exposed connections.

TDS 684A, TDS 744A, & TDS 784A Service Manual xiii Service Safety Summary Only qualified personnel should perform service procedures. Read this ServiceSafety Summary and the General Safety Summary before performing any serviceprocedures. Do not perform internal service or adjustments of this pro...

Page 18 - xiv

Service Safety Summary xiv TDS 684A, TDS 744A, & TDS 784A Service Manual

Page 19 - xv; Preface; Manual Structure

TDS 684A, TDS 744A, & TDS 784A Service Manual xv Preface This preface contains information needed to properly use this manual to servicethe TDS 684A and 7XXA Digitizing Oscilloscopes, as well as general informa-tion critical to safe and effective servicing of this oscilloscope. Manual Structure ...

Page 20 - xvi; Manual Conventions; STOP; Related Manuals; Modules

Preface xvi TDS 684A, TDS 744A, & TDS 784A Service Manual H Diagrams contains a block diagram and an interconnection diagram usefulfor isolating failed modules. H Mechanical Parts List includes a table of all replaceable modules, theirdescriptions, and their Tektronix part numbers. Manual Conven...

Page 21 - xvii

Preface TDS 684A, TDS 744A, & TDS 784A Service Manual xvii TDS Family (400, 5XXA, 6XXA, and 7XXA) Programmer Manual (Tektronix partnumber 070-8709-XX) contains information for programmed operation via theGPIB interface. Included is the complete command set, setup information, andprogramming exam...

Page 22 - xviii

Preface xviii TDS 684A, TDS 744A, & TDS 784A Service Manual

Page 23 - xix; Introduction; Service Strategy; Service Offerings; Warranty Repair Service

TDS 684A, TDS 744A, & TDS 784A Service Manual xix Introduction Service Strategy STOP . Throughout this manual, any field-replaceable component, assembly, or part of this oscilloscope is referred to generically as a module. This manual contains all the information needed for periodic maintenance ...

Page 24 - Self Service

Introduction xx TDS 684A, TDS 744A, & TDS 784A Service Manual Option 9C. When you order the TDS 684A and 7XXA Digitizing Oscilloscopes with option 9C, each one is shipped with a Certificate of Calibration and TestData Report. This certificate provides traceability to the National Institute ofSta...

Page 25 - xxi; Before You Begin; Be sure you are a qualified service person.

Introduction TDS 684A, TDS 744A, & TDS 784A Service Manual xxi Before You Begin This manual is for servicing the TDS 684A and 7XXA Digitizing Oscilloscopes.To prevent injury to yourself or damage to the oscilloscope, do the followingtasks before you attempt service: H Be sure you are a qualified...

Page 26 - xxii

Introduction xxii TDS 684A, TDS 744A, & TDS 784A Service Manual

Page 28 - Product Description; Table 1–1: Key Features of the TDS 684A and 7XXA Oscilloscopes; Feature

TDS 684A, TDS 744A, & TDS 784A Service Manual 1–1 Specifications This section begins with a general description of the traits of the TDS 684A and7XXA Digitizing Oscilloscopes. Three sections follow, one for each of threeclasses of traits: nominal traits, warranted characteristics, and typical ch...

Page 29 - User Interface; Menus

Specifications 1–2 TDS 684A, TDS 744A, & TDS 784A Service Manual User Interface Use a combination of front-panel buttons, knobs, and on-screen menus to controlthe many functions of the oscilloscope. The front-panel controls are groupedaccording to function: vertical, horizontal, trigger, and spe...

Page 30 - Horizontal System; Record Length

Specifications TDS 684A, TDS 744A, & TDS 784A Service Manual 1–3 Besides these channels, up to three math waveforms and four reference wave-forms are available for display. (A math waveform results when you specify dualwaveform operations, such as add, on any two channels. A reference waveformre...

Page 31 - Trigger System; (flexible format) allows the user to define the video; Acquisition Control

Specifications 1–4 TDS 684A, TDS 744A, & TDS 784A Service Manual The delayed display (or the intensified zone) may also be delayed by a selectednumber of events. In this case, the events source is the delayed-trigger source.The delayed trigger can also be set to occur after a number of events pl...

Page 32 - On-Board User Assistance; Help

Specifications TDS 684A, TDS 744A, & TDS 784A Service Manual 1–5 H Select the mode for interpolation (linear or sin (x)/x). This can increase theapparent sample rate on the waveform when the maximum real-time rate isexceeded. H Use sample, envelope, and average modes to acquire signals.With the ...

Page 33 - Storage; Measure

Specifications 1–6 TDS 684A, TDS 744A, & TDS 784A Service Manual with respect to the trigger point (event) of the acquisition. The cursors can alsocontrol the portion of the waveform on which automatic measurements are made. For time measurements, units can be either seconds or hertz (for 1/time...

Page 34 - Display; Zoom

Specifications TDS 684A, TDS 744A, & TDS 784A Service Manual 1–7 The oscilloscope can also output copies of its display using the hardcopy feature.This feature allows you to output waveforms and other on-screen information toa variety of graphic printers and plotters from the TDS front panel, pr...

Page 36 - Nominal Traits; Table 1–3: Nominal Traits — Signal Acquisition System; Name

TDS 684A, TDS 744A, & TDS 784A Service Manual 1–9 Nominal Traits This section contains a collection of tables that list the various nominal traitsthat describe the TDS 684A and 7XXA oscilloscopes. Electrical and mechanicaltraits are included. Nominal traits are described using simple statements ...

Page 37 - Table 1–4: Nominal Traits — Time Base System; Table 1–5: Nominal Traits — Triggering System

Nominal Traits 1–10 TDS 684A, TDS 744A, & TDS 784A Service Manual Table 1–4: Nominal Traits — Time Base System Name Description Range, Sample-Rate 1,3 TDS 684A; 5 Samples/sec to 5 GSamples/sec on four channels simultaneously TDS 744A: 5 Samples/sec to 2 GSamples/sec when acquiring 1 channelto 1 ...

Page 38 - Table 1–6: Nominal Traits — Display System

Nominal Traits TDS 684A, TDS 744A, & TDS 784A Service Manual 1–11 Table 1–5: Nominal Traits — Triggering System (Cont.) Name Description Ranges, Setup and Hold for TimeSetup/Hold Violation Trigger Feature Min to max Ranges, Setup and Hold for TimeSetup/Hold Violation Trigger Setup Time Hold Time...

Page 39 - Table 1–8: Nominal Traits — Data Handling and Reliability

Nominal Traits 1–12 TDS 684A, TDS 744A, & TDS 784A Service Manual Table 1–7: Nominal Traits — GPIB Interface, Output Ports, and Power Fuse Name Description Interface, GPIB GPIB interface complies with IEEE Std 488-1987 Interface, RS-232 RS-232 interface complies with EIA/TIA 574 (talk only) Inte...

Page 40 - Table 1–9: Nominal Traits — Mechanical

Nominal Traits TDS 684A, TDS 744A, & TDS 784A Service Manual 1–13 Table 1–9: Nominal Traits — Mechanical Name Description Cooling Method Forced-air circulation with no air filter. Clearance is required. Construction Material Chassis parts constructed of aluminum alloy; front panel constructed of...

Page 42 - Warranted Characteristics; NOTE; Performance Conditions; C of the current ambient temperature.

TDS 684A, TDS 744A, & TDS 784A Service Manual 1–15 Warranted Characteristics This section lists the various warranted characteristics that describe theTDS 684A and 7XXA Digitizing Oscilloscopes. Electrical and environmentalcharacteristics are included. Warranted characteristics are described in ...

Page 43 - Table 1–10: Warranted Characteristics — Signal Acquisition System

Warranted Characteristics 1–16 TDS 684A, TDS 744A, & TDS 784A Service Manual Table 1–10: Warranted Characteristics — Signal Acquisition System Name Description Accuracy, DC Gain TDS 684A: ± 1.5% for all sensitivities from 2 mV/div to 10 V/div ± 2.0% at 1 mV/div sensitivity TDS 7XXA: ± 1% for all...

Page 44 - Table 1–11: Warranted Characteristics — Time Base System

Warranted Characteristics TDS 684A, TDS 744A, & TDS 784A Service Manual 1–17 Table 1–10: Warranted Characteristics — Signal Acquisition System (Cont.) Name Description Analog Bandwidth, DC-1M Coupled with P6139A Probe and Bandwidthselection is FULL Volts/Div asRead Out onScreen 684A Bandwidth 2 ...

Page 45 - Table 1–12: Warranted Characteristics — Triggering System

Warranted Characteristics 1–18 TDS 684A, TDS 744A, & TDS 784A Service Manual Table 1–12: Warranted Characteristics — Triggering System Name Description Sensitivity, Edge-Type Trigger, Couplingset to “DC” 1 Trigger Source Sensitivity Sensitivity, Edge-Type Trigger, Couplingset to “DC” 1 Any Chann...

Page 46 - Table 1–14: Warranted Characteristics — Environmental

Warranted Characteristics TDS 684A, TDS 744A, & TDS 784A Service Manual 1–19 Table 1–13: Warranted Characteristics — Output Ports, Probe Compensator, and Power Requirements (Cont.) Name Description Power Consumption ≤ 300 W (450 VA) 1 CH 3 signal out is present at the rear panel if CH 3 is selec...

Page 48 - Typical Characteristics; Table 1–15: Typical Characteristics — Signal Acquisition System

TDS 684A, TDS 744A, & TDS 784A Service Manual 1–21 Typical Characteristics This subsection contains tables that list the various typical characteristics whichdescribe the TDS 684A and 7XXA Digitizing Oscilloscopes. Typical characteristics are described in terms of typical or average performance....

Page 50 - Table 1–16: Typical Characteristics — Triggering System

Typical Characteristics TDS 684A, TDS 744A, & TDS 784A Service Manual 1–23 Table 1–16: Typical Characteristics — Triggering System Name Description Accuracy, Trigger Level or Threshold,DC Coupled Trigger Source Accuracy Accuracy, Trigger Level or Threshold,DC Coupled(for signals having rise and ...

Page 55 - Installation; Supplying Operating Power; Power Cord Information

TDS 684A, TDS 744A, & TDS 784A Service Manual 2–1 Installation Supplying Operating Power NOTE . Read all information and heed all warnings in this subsection before connecting the oscilloscope to a power source. WARNING. AC POWER SOURCE AND CONNECTION. The oscilloscope operates from a single-pha...

Page 56 - Table 2–1: Power-Cord Conductor Identification; This oscilloscope operates with any line voltage from 90–250 VAC; with any; Operating Voltage

Installation 2–2 TDS 684A, TDS 744A, & TDS 784A Service Manual Table 2–1: Power-Cord Conductor Identification Conductor Color Alternate Color Ungrounded (Line) Brown Black Grounded (Neutral) Light Blue White Grounded (Earthing) Green/Yellow Green Table 2–2: Power Cord Identification Plug Configu...

Page 57 - Operating Environment; C for the TDS 7XXA) with no diskette in the floppy drive.; Applying and Interrupting Power; Memory Backup Power

Installation TDS 684A, TDS 744A, & TDS 784A Service Manual 2–3 Memory modules with on-board batteries allow the TDS 684A and 7XXA Digi-tizing Oscilloscopes to retain some types of data upon loss of the AC powersource. The stored adjustment constants, saved front-panel settings, currentfront-pane...

Page 58 - Table 2–3: Effects of Corrupted Data; Corrupted Data Type; Repackaging Instructions; Power Off

Installation 2–4 TDS 684A, TDS 744A, & TDS 784A Service Manual continue. See Section 6, Maintenance, for information on diagnostics and faultisolation. CAUTION. DO NOT power off the oscilloscope when either running a signal path compensation or when doing any of the adjustments described in Sect...

Page 59 - Installed Options

Installation TDS 684A, TDS 744A, & TDS 784A Service Manual 2–5 Seal the shipping carton with an industrial stapler or strapping tape. Mark the address of the Tektronix Service Center and also your own returnaddress on the shipping carton in two prominent locations. Installed Options Your instrum...

Page 61 - Operating Instructions; Screen Layout; The principal power switch at the rear panel is the true power; How to Power On

TDS 684A, TDS 744A, & TDS 784A Service Manual 2–7 Operating Instructions Before doing service, read the following operating instructions. These instruc-tions are at the level appropriate for servicing these Digitizing Oscilloscopes.The User Manual contains more complete operating instructions. A...

Page 62 - Figure 2–1: Map of Display Functions; How to Use Help

Operating Instructions 2–8 TDS 684A, TDS 744A, & TDS 784A Service Manual Brief status information Position of waveform record relative to the screen and display General purpose knob readout Waveform reference symbols shows ground levels and waveform sources Graticule and waveforms Side menu area...

Page 63 - Locate the block that contains the function to be set.; How to Set Functions

Operating Instructions TDS 684A, TDS 744A, & TDS 784A Service Manual 2–9 Most functions can be set either by using one (or two) front-panel button(s) orknob(s), or by pushing a front-panel button to use a main menu, and then aside-menu button to set the function. The following steps illustrate b...

Page 66 - b. Pushing the button that popped up the menu (17) toggles through the; How to Set Complex

Operating Instructions 2–12 TDS 684A, TDS 744A, & TDS 784A Service Manual e. Select the setting for the function from the side menu (9) using theside-menu buttons (11). Example: Push AC (10). A few functions require more than just two levels (main and side) of menus tocompletely specify their se...

Page 67 - a. Pushing some main-menu buttons displays a side menu with labels; As you’ve just seen, the general purpose

Operating Instructions TDS 684A, TDS 744A, & TDS 784A Service Manual 2–13 2. Set up a function using the general purpose knob (20). (The examples of possible menu selections in the substeps that follow assume you’ve pushedTRIGGER MENU.) 19 20 21 a. Pushing some main-menu buttons displays a side ...

Page 69 - Display and Utility Menus.; Using the techniques described for using menus, you

Operating Instructions TDS 684A, TDS 744A, & TDS 784A Service Manual 2–15 Display and Utility Menus. Using the techniques described for using menus, you can access and change functions in the display menu and utilities menu. In theDisplay menu, you can set the following functions: H Color: wavef...

Page 72 - Theory of Operation; This section has two main parts:; Logic Conventions; input termination is; General

TDS 684A, TDS 744A, & TDS 784A Service Manual 3–1 Theory of Operation This section describes the electrical operation of the TDS 684A and 7XXA Digi-tizing Oscilloscopes using the major circuit blocks or modules. This section has two main parts: H Logic Conventions describes how logic functions a...

Page 73 - Probe Coding Interface.; Tube Assembly

Theory of Operation 3–2 TDS 684A, TDS 744A, & TDS 784A Service Manual selected and the input is overloaded, the processor system switches the input tothe 1 M W position. Probe Coding Interface. Probe coding interface signals pass through the attenuator portion of the A10 Attenuator/Acquisition t...

Page 74 - Front Panel

Theory of Operation TDS 684A, TDS 744A, & TDS 784A Service Manual 3–3 The processor system sends instructions to and receives information from theFront Panel Processor on the A12 Front Panel board. The Front Panel Processorreads the front-panel switches and potentiometers. Any changes in their s...

Page 77 - Performance Verification Procedures

TDS 684A, TDS 744A, & TDS 784A Service Manual 4–1 Performance Verification Procedures Two types of Performance Verification procedures can be performed on thisproduct; Brief Procedures and Performance Tests. You may not need to performall of these procedures, depending on what you want to accomp...

Page 78 - Conventions

Performance Verification Procedures 4–2 TDS 684A, TDS 744A, & TDS 784A Service Manual Conventions Throughout these procedures the following conventions apply: H Each test procedure uses the following general format: Title of Test Equipment Required Prerequisites Procedure H Each procedure consis...

Page 79 - Figure 4–1: Map of Display Functions

Performance Verification Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 4–3 the five buttons to the right of the display. “Pop-up menu” refers to a menuthat pops up when a main-menu button is pressed. Brief status information Position of waveform record relative to the screen and displ...

Page 81 - Brief Procedures; Self Tests; Prerequisites; passing of internal diagnostics.; Verify Internal Adjustment,

TDS 684A, TDS 744A, & TDS 784A Service Manual 4–5 Brief Procedures The Self Tests use internal routines to confirm basic functionality and properadjustment. No test equipment is required to do these test procedures. The Functional Tests utilize the probe-compensation output at the front panel as...

Page 82 - Figure 4–2: Verifying Adjustments and Signal-Path Compensation

Brief Procedures 4–6 TDS 684A, TDS 744A, & TDS 784A Service Manual e. Confirm the three adjustment sections have passed status: H Press SHIFT; then press UTILITY. H Highlight Cal in the pop-up menu by repeatedly pressing themain-menu button System. See Figure 4–2. H Verify that the word Pass app...

Page 83 - Functional Tests; The optional P6245 probes that can be used with this oscilloscope

Brief Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 4–7 2. Return to regular service: Press CLEAR MENU to exit the system menus. Functional Tests The purpose of these procedures is to confirm that the oscilloscope functionsproperly. The only equipment required is one of the standard-a...

Page 84 - Install the test hookup and preset the oscilloscope controls:; Press the main-menu button Recall Factory Setup.; Verify All Input Channels

Brief Procedures 4–8 TDS 684A, TDS 744A, & TDS 784A Service Manual EquipmentRequired One probe such as the P6245 or P6139A Prerequisites None 1. Install the test hookup and preset the oscilloscope controls: a. Hook up the signal source: Install the probe on CH 1. Connect the probe tip to PROBE C...

Page 86 - Set the vertical SCALE to 200 mV.; Verify the Time Base

Brief Procedures 4–10 TDS 684A, TDS 744A, & TDS 784A Service Manual H Sample mode displays an actively acquiring waveform on-screen.(Note that there is noise present on the peaks of the square wave.) H Peak Detect mode (TDS 7XXA only) displays an actively acquiringwaveform on-screen with the noi...

Page 87 - Verify the Main and

Brief Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 4–11 a. One period of the square-wave probe-compensation signal is about five horizontal divisions on-screen for the 200 m s horizontal scale setting (set in step 1c). b. Rotating the horizontal SCALE knob clockwise expands the wavef...

Page 88 - Press HORIZONTAL MENU.; b. Select the delayed trigger level menu:

Brief Procedures 4–12 TDS 684A, TDS 744A, & TDS 784A Service Manual 2. Verify that the main trigger system operates: Confirm that the following statements are true. H The trigger level readout for the main trigger system changes with thetrigger-LEVEL knob. H The trigger-LEVEL knob can trigger an...

Page 89 - Verify the File System

Brief Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 4–13 H Verify that the trigger READY indicator on the front panel flashesabout once every second as the waveform is updated on-screen. 4. Remove the test hookup: Disconnect the probe from the channel input and the probe-compensation ...

Page 91 - Performance Tests; The cabinet must be installed on the Digitizing Oscilloscope.

TDS 684A, TDS 744A, & TDS 784A Service Manual 4–15 Performance Tests This section contains a collection of procedures for checking that the TDS 684Aand 7XXA Digitizing Oscilloscopes perform as warranted. The procedures are arranged in four logical groupings: Signal Acquisition SystemChecks, Time...

Page 92 - Equipment Required; Table 4–1: Test Equipment; Minimum Requirements

Performance Tests 4–16 TDS 684A, TDS 744A, & TDS 784A Service Manual Equipment Required These procedures use external, traceable signal sources to directly checkwarranted characteristics. The required equipment list follows this introduction. Table 4–1: Test Equipment Item Number and Description...

Page 93 - Purpose

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–17 Table 4–1: Test Equipment (Cont.) Item Number and Description Purpose Example Minimum Requirements 15. 3.5 inch, 720 K or 1.44 Mbyte, DOS-com-patible floppy disk Programming ExamplesSoftware Disk (Tektronix partnumber 063-1134-...

Page 95 - TDS 684A Test Record; TDS 684A Performance Test

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–19 TDS 684A Test Record Photocopy this and the next three pages and use them to record the performancetest results for your TDS 684A. TDS 684A Test Record Instrument Serial Number: Certificate Number: Temperature: RH %: Date of Ca...

Page 99 - TDS 7XXA Test Record; TDS 7XXA Performance Test

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–23 TDS 7XXA Test Record Photocopy this and the next three pages and use them to record the performancetest results for your TDS 7XXA. TDS 7XXA Test Record Instrument Serial Number: Certificate Number: Temperature: RH %: Date of Ca...

Page 103 - Signal Acquisition System Checks; Be sure to disconnect any input signals from all four channels.; Check Offset Accuracy

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–27 Signal Acquisition System Checks These procedures check those characteristics that relate to the signal-acquisitionsystem and are listed as checked under Warranted Characteristics in Specifica-tions. EquipmentRequired None Prer...

Page 104 - Vertical position is set to 0 divisions and vertical offset to; Enter voltage on test record.

Performance Tests 4–28 TDS 684A, TDS 744A, & TDS 784A Service Manual b. Set the vertical scale: Set the vertical SCALE to one of the settings listed in Table 4–2 that is not yet checked. (Start with the first settinglisted.) H Press VERTICAL MENU. Press the main-menu button Fine Scale. H Use the...

Page 105 - Figure 4–4: Measurement of DC Offset Accuracy at Zero Setting; Check DC Voltage

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–29 Align the active cursor over the waveform. 1 Read the measurement results. 2 Figure 4–4: Measurement of DC Offset Accuracy at Zero Setting g. Test all channels: Repeat substeps a through f for all input channels. 3. Disconnect ...

Page 106 - Install the test hookup and preset the instrument controls:; Figure 4–5: Initial Test Hookup; Modify the default settings:

Performance Tests 4–30 TDS 684A, TDS 744A, & TDS 784A Service Manual 1. Install the test hookup and preset the instrument controls: a. Hook up the test-signal source: H Set the output of a DC calibration generator to 0 volts. H Connect the output of a DC calibration generator through adual-banan...

Page 107 - Table 4–3: DC Accuracy

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–31 a. Select an unchecked channel: H Press WAVEFORM OFF to remove the channel just confirmedfrom the display. H Press the front-panel button that corresponds to the channel you areto confirm. H Set the generator output to 0 V. H M...

Page 108 - Check against limits:

Performance Tests 4–32 TDS 684A, TDS 744A, & TDS 784A Service Manual H Use the keypad to set vertical offset to the positive-polarity settinglisted in the table for the current vertical scale setting. The baselinelevel will remain off screen. H Set the generator to the level and polarity indicat...

Page 109 - Check Analog Bandwidth

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–33 H Repeat substeps c through f until all vertical scale settings, listed inTable 4–3, are checked for the channel under test. g. Test all channels: Repeat substeps a through f for all four channels. 3. Disconnect the hookup: a. ...

Page 110 - Figure 4–7: Initial Test Hookup; Move the leveling head to the channel you selected.; button to toggle it to the 50

Performance Tests 4–34 TDS 684A, TDS 744A, & TDS 784A Service Manual High Frequency Sine Wave Generator Digitizing Oscilloscope Output Leveling Head Figure 4–7: Initial Test Hookup 2. Confirm the input channels are within limits for analog bandwidth: Do the following substeps — test CH 1 first, ...

Page 111 - Table 4–4: Analog Bandwidth; Vertical Scale

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–35 Table 4–4: Analog Bandwidth Vertical Scale Attenuators(10X) Reference Amplitude (at6 MHz) HorizontalScale TDS 684Aand 784ATest Frequency TDS 744ATest Frequency Limits 100 mV none 600 mV (6 divisions) 1 ns 1 GHz 500 MHz ≥ 424 mV...

Page 112 - Figure 4–8: Measurement of Analog Bandwidth

Performance Tests 4–36 TDS 684A, TDS 744A, & TDS 784A Service Manual f. Measure the test signal: H Set the frequency of the generator, as shown on screen, to the testfrequency in Table 4–4 that corresponds to the vertical scale set insubstep d. See Figure 4–8. H Set the horizontal SCALE to the h...

Page 113 - Check Delay Between

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–37 STOP . Checking each channel’s bandwidth at all vertical scale settings is time consuming and unnecessary. You may skip checking the remaining vertical scalesettings in Table 4–4 (that is, skip the following substep, h) if this...

Page 114 - Figure 4–9: Initial Test Hookup

Performance Tests 4–38 TDS 684A, TDS 744A, & TDS 784A Service Manual STOP . DO NOT use the vertical position knob to reposition any channel while doing this check. To do so invalidates the test. 1. Install the test hookup and preset the instrument controls: a. Initialize the front panel: H Press...

Page 115 - b. The horizontal SCALE should already be set to 500 ps. On the TDS; Display all test signals:; Press WAVEFORM OFF to remove CH 3 from the display.; Measure the test signal:

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–39 2. Confirm all four channels (CH 1 through CH 4) are within limits for channel delay: a. Set up the generator: Set the generator frequency to 250 MHz and the amplitude for about six divisions in CH 1. Hint: As you are adjusting...

Page 116 - Figure 4–10: Measurement of Channel Delay – TDS 684A Shown; g. Check against limits: CHECK that the cursor readout on screen is

Performance Tests 4–40 TDS 684A, TDS 744A, & TDS 784A Service Manual H Press the main-menu button Function; then press the side-menubutton V Bars. H Press CLEAR MENU. H Align one V bar cursor to the time reference point of the left-mostwaveform edge and the other cursor to the time reference poi...

Page 117 - k. Again use the cursors to measure the skew from CH1 to CH2, CH1 to; n. Add the first CH1 to CH4 skew measurement to the second CH1 to CH4; skew measurement and divide the result by 2. Use Table 4–5.; Table 4–5: Delay Between Channels Worksheet; Coupling; the input connectors of the channels.

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–41 ment column of Table 4–5. Note that these numbers may be eitherpositive or negative. j. Repeat the procedure from step 1.c through 2.e., 4th bullet item. k. Again use the cursors to measure the skew from CH1 to CH2, CH1 to CH3,...

Page 118 - Time Base System Checks; Figure 4–11: Initial Test Hookup; Set the vertical SCALE to 500 mV.; Check Accuracy for

Performance Tests 4–42 TDS 684A, TDS 744A, & TDS 784A Service Manual Time Base System Checks These procedures check those characteristics that relate to the Main and Delayedtime base system and are listed as checked under Warranted Characteristics inSpecifications. EquipmentRequired One time-mar...

Page 119 - Set the horizontal SCALE of the Main time base to 1 ms.; Enter number of divisions on test record.

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–43 H Set the horizontal SCALE of the Main time base to 1 ms. H Press TRIGGER MENU; then press the main-menu button Mode& Holdoff. Press the side-menu button Normal. 2. Confirm Main and Delayed time bases are within limits for ...

Page 120 - Figure 4–12: Measurement of Accuracy — Long-Term and Delay Time; Trigger System Checks; Pulse-Width Triggering

Performance Tests 4–44 TDS 684A, TDS 744A, & TDS 784A Service Manual Check long–term sample rates and delay time accuracies against limits. 4 Align the trigger T to the center graticule line. 1 Sethorizontalmode. 2 Set horizontal scale and delayed time. 3 Figure 4–12: Measurement of Accuracy — L...

Page 121 - Figure 4–13: Initial Test Hookup; pulse-width triggering (Horizontal Scale

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–45 1. Install the test hookup and preset the instrument controls: a. Initialize the instrument: H Press save/recall SETUP. H Press the main-menu button Recall Factory Setup. H Press the side-menu button OK Confirm Factory Init. b....

Page 123 - Set the horizontal SCALE to 5

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–47 Set upperand lowerlimits thatensuretriggering.Then changelimits untiltriggeringstops. Figure 4–14: Measurement of Time Accuracy for Pulse and Glitch Triggering 3. Confirm the trigger system is within time-accuracy limits for pu...

Page 124 - Figure 4–15: Initial Test Hookup; Threshold, DC Coupled

Performance Tests 4–48 TDS 684A, TDS 744A, & TDS 784A Service Manual H CHECK that the Lower Limit readout, after the oscilloscope stopstriggering, is within 1 m s to 3 m s, inclusive, for the TDS 684A or is within 1.9 m s to 2.1 m s, inclusive, for the TDS 7XXA. H Enter time on test record. H Us...

Page 126 - Figure 4–16: Measurement of Trigger-Level Accuracy

Performance Tests 4–50 TDS 684A, TDS 744A, & TDS 784A Service Manual c. Read results (Check against limits): See Figure 4–16. H CHECK that the Level readout in the main menu is within 9.863 Vto 10.137 V, inclusive, for the TDS 684A or is within 9.9393 V to10.1147 V, inclusive, for the TDS 7XXA. ...

Page 128 - to select the 50; DC Coupled

Performance Tests 4–52 TDS 684A, TDS 744A, & TDS 784A Service Manual EquipmentRequired One medium-frequency leveled sine wave generator (Item 11) One high-frequency leveled sine wave generator (Item 12) Two precision 50 coaxial cables (Item 5) One 10X attenuator (Item 1) One BNC T connector (Ite...

Page 129 - Figure 4–17: Initial Test Hookup; b. Check the Main trigger system for stable triggering at limits:

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–53 the other output of the T connector to the AUX TRIG INPUT at the rear panel. See Figure 4–17. Medium Frequency Sine Wave Generator Digitizing Oscilloscope To AUX TRIG INPUT on Rear Panel Figure 4–17: Initial Test Hookup 2. Conf...

Page 132 - Set the horizontal SCALE to 500 ps for the M (Main) time base.; Display the test signal:

Performance Tests 4–56 TDS 684A, TDS 744A, & TDS 784A Service Manual H Press SET LEVEL TO 50%. CHECK that a stable trigger isobtained for the test waveform on both the positive and negativeslopes. Press the main-menu button Slope; then use the side menu toswitch between trigger slopes. Use the T...

Page 133 - Output Signal Checks; Figure 4–19: Initial Test Hookup; Set the output of the calibration generator to 0.500 V.; panel to CH 2 through a 50; Initialize the oscilloscope:; Check Outputs — CH 3

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–57 NOTE . You just checked the trigger sensitivity. If desired, you may repeat steps 1 through 4 for the other channels (CH2, CH3, and CH4). 5. Disconnect the hookup: Disconnect the cable from the channel last tested. Output Signa...

Page 134 - Check Main Trigger output against limits:; Low readout is

Performance Tests 4–58 TDS 684A, TDS 744A, & TDS 784A Service Manual H Press save/recall SETUP. H Press the main-menu button Recall Factory Setup. H Press the side-menu button OK Confirm Factory Init. d. Modify the initialized front-panel control settings: H Set the horizontal SCALE to 200 m s. ...

Page 135 - Figure 4–20: Measurement of Main Trigger Out Limits

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–59 Check output Figure 4–20: Measurement of Main Trigger Out Limits d. Check Delayed Trigger output against limits: See Figure 4–20. H Move the precision 50 W cable from the rear-panel Main Trigger Output BNC to the rear-panel Del...

Page 136 - Check Probe

Performance Tests 4–60 TDS 684A, TDS 744A, & TDS 784A Service Manual H Press the main-menu button Source. H Press the side-menu button Ch3. H Set vertical SCALE to 100 mV. H Press SET LEVEL TO 50%. H Press MEASURE; then press the main-menu button SelectMeasrmnt for Ch2. H Repeatedly press the si...

Page 137 - Figure 4–21: Initial Test Hookup; Modify the initialized front-panel control settings:

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–61 1. Install the test hookup and preset the instrument controls: a. Hook up test-signal: H Connect one of the 50 W cables to CH 1. See Figure 4–21. H Connect the other end of the cable just installed to the femaleBNC-to-clips ada...

Page 138 - Figure 4–22: Measurement of Probe Compensator Frequency; Save the probe compensation signal in reference memory:

Performance Tests 4–62 TDS 684A, TDS 744A, & TDS 784A Service Manual H Select 128 averages. 2. Confirm that the Probe Compensator signal is within limits for frequency: a. Measure the frequency of the probe compensation signal: H Press MEASURE; then press the main-menu button SelectMeasrmnt for ...

Page 139 - Figure 4–23: Subsequent Test Hookup; Measure amplitude of the probe compensation signal:

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–63 H Press SAVE/RECALL WAVEFORM; then press the main-menubutton Save Wfm Ch 1. H Press the side-menu button To Ref 1 to save the probe compensationsignal in reference 1. H Disconnect the cable from CH 1 and the clips from the prob...

Page 140 - Figure 4–24: Measurement of Probe Compensator Amplitude; Enter voltage difference on test record.

Performance Tests 4–64 TDS 684A, TDS 744A, & TDS 784A Service Manual H Adjust the output of the DC calibration generator until it preciselyoverlaps the top (upper) level of the stored probe compensationsignal. (This value will be near 500 mV.) H Record the setting of the DC generator. H Adjust t...

Page 141 - Option 05 Video Trigger Checks; Press the side-menu OK Confirm Factory Init.; CONFIRM the digitizing oscilloscope is setup as shown below.; Check Video Trigger

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–65 Option 05 Video Trigger Checks EquipmentRequired PAL signal source (Item 16) 60 Hz. sine wave generator (Item 17) Pulse generator (Item 18) Two 75 cables (Item 19) Two 75 terminators (Item 20) One BNC T connector (Item 7) 50 ca...

Page 142 - Figure 4–25: Jitter Test Hookup; it displays the waveform on screen. See Figure 4–26.

Performance Tests 4–66 TDS 684A, TDS 744A, & TDS 784A Service Manual g. Press the main-menu Bandwidth. h. Select 250 MHz from the side menu. i. Press the main-menu Fine Scale. j. Use the keypad to set the fine scale to 282mV (press 282, SHIFT, m,then ENTER). k. Press HORIZONTAL MENU. l. Press th...

Page 143 - Figure 4–26: Jitter Test Displayed Waveform – TDS 684A Shown

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–67 Figure 4–26: Jitter Test Displayed Waveform – TDS 684A Shown c. Press SHIFT; then press ACQUIRE MENU. d. Press the main-menu Mode. e. Select the side-menu Average. It should be already set to 16. f. Press the main-menu Create L...

Page 144 - Figure 4–27: Jitter Test When Completed – TDS 684A Shown; Set up oscilloscope for Triggered Signal Test.

Performance Tests 4–68 TDS 684A, TDS 744A, & TDS 784A Service Manual q. Press the main-menu Mode. r. Press the side-menu Envelope. s. Use the keypad to set envelope to use 100 acquisitions (press 100, thenENTER). t. Press the main-menu Stop After button. u. Press the side-menu Single Acquisition...

Page 146 - Figure 4–28: Triggered Signal Range Test – 300 mV

Performance Tests 4–70 TDS 684A, TDS 744A, & TDS 784A Service Manual Positive pulse Negative pulses Figure 4–28: Triggered Signal Range Test – 300 mV n. Use the keypad to set the fine scale to 75 mV (press 75, SHIFT, m, then ENTER). o. CONFIRM that the TRIG’D LED stays lighted and that the wavef...

Page 147 - Figure 4–29: Triggered Signal Range Test – 75 mV; Connect the output of the SG 502 to the CH2 input through a 50

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–71 Positive pulse Negative pulses Figure 4–29: Triggered Signal Range Test – 75 mV p. Disconnect all test equipment (TSG121) from the digitizing oscillo- scope. 5. Check 60 Hz Rejection. a. Set up oscilloscope for 60 Hz Rejection ...

Page 148 - Figure 4–30: 60 Hz Rejection Test Hookup; Check 60 Hz rejection.

Performance Tests 4–72 TDS 684A, TDS 744A, & TDS 784A Service Manual Digitizing Oscilloscope 50 Cable Signal Generator Output Figure 4–30: 60 Hz Rejection Test Hookup H Adjust the SG 502 for three vertical divisions of 60 Hz signal. SeeFigure 4–31. The signal will not be triggered. That is, it w...

Page 149 - Figure 4–32: Subsequent 60 Hz Rejection Test Hookup; Disconnect all test equipment from the digitizing oscilloscope.

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–73 COMPST on the TSG 121) to a 75 W cable and a 75 W terminator. Connect both signals to the CH1 input through a BNC T. SeeFigure 4–32. H Press VERTICAL MENU. H If needed, press the main-menu Fine Scale. H Use the keypad to set fi...

Page 150 - Figure 4–33: 60 Hz Rejection Test Result – TDS 684A Shown; cable and a 75

Performance Tests 4–74 TDS 684A, TDS 744A, & TDS 784A Service Manual Figure 4–33: 60 Hz Rejection Test Result – TDS 684A Shown 6. Check Line Count Accuracy. a. Set up oscilloscope for Line Count Accuracy Test. H Press WAVEFORM OFF. H Press CH1. H Press HORIZONTAL MENU. H Press the main-menu Reco...

Page 151 - Figure 4–34: Line Count Accuracy Test Hookup

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–75 PAL Signal Source Digitizing Oscilloscope 75 Cable 75 Terminator Output Figure 4–34: Line Count Accuracy Test Hookup H Press the main-menu Trigger Position. H Press the side-menu to Set to 50%. H Press the main-menu to Horiz Po...

Page 152 - Figure 4–35: Line Count Accuracy Test Setup Waveform – TDS 684A Shown

Performance Tests 4–76 TDS 684A, TDS 744A, & TDS 784A Service Manual Figure 4–35: Line Count Accuracy Test Setup Waveform – TDS 684A Shown H Press CURSOR. H Press the main-menu Function. H Press the side-menu V Bars. H Using the General Purpose knob, place the left cursor directly overthe trigge...

Page 153 - Figure 4–36: Line Count Accuracy Correct Result Waveform

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–77 Figure 4–36: Line Count Accuracy Correct Result Waveform H Disconnect all test equipment (TSG 121) from the digitizingoscilloscope. H Turn off cursors by pressing CURSOR, then the main-menuFunction button, and, finally, Off fro...

Page 155 - Figure 4–37: PG502 Setup for Sync Duty Cycle Test

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–79 c. Check Sync Duty Cycle. H Connect the pulse generator (PG502) through a 50 W cable and a 50 W terminator to the oscilloscope CH1 input. See Figure 4–37. Pulse Generator Digitizing Oscilloscope 50 Cable 50 Terminator Output Fi...

Page 156 - Figure 4–38: Sync Duty Cycle Test: One-Div Neg Pulse Waveform

Performance Tests 4–80 TDS 684A, TDS 744A, & TDS 784A Service Manual Figure 4–38: Sync Duty Cycle Test: One-Div Neg Pulse Waveform H Turn the pulse generator PULSE DURATION variable control toadjust the negative pulse so the oscilloscope’s CH1 – Widthmeasurement displays 400ns +/–10 ns. H Turn t...

Page 157 - Figure 4–39: Sync Duty Cycle Test: Critically Adjusted Pulse

Performance Tests TDS 684A, TDS 744A, & TDS 784A Service Manual 4–81 Figure 4–39: Sync Duty Cycle Test: Critically Adjusted Pulse H Press TRIGGER MENU. H Press the main-menu Type pop-up until you select Video. If the TRIG’D LED is not lighted, check that the CH1 – Width andCH1 Period measurement...

Page 160 - The Adjustment Procedures are divided into six subsections:; Requirements for Performance; This oscilloscope requires a 20 minute warm-up time in a 20; Description

TDS 684A, TDS 744A, & TDS 784A Service Manual 5–1 Adjustment Procedures This section contains information needed to adjust the TDS 684A and 7XXA Digitizing Oscilloscopes. The Adjustment Procedures are divided into six subsections: H General information about adjusting the TDS 684A and 7XXA Digit...

Page 161 - Usage; System

Adjustment Procedures 5–2 TDS 684A, TDS 744A, & TDS 784A Service Manual Two small holes in the chassis allow service personnel to insert a tool and push aswitch to enable or disable the writing of new adjustment constants to nonvola-tile RAM. The procedure that follows will tell you how and when...

Page 162 - Table 5–1: Calibration Tests; Class of Adjustment; Complete Adjustment

Adjustment Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 5–3 Since the display-assembly and P6139A probe adjustment require manualadjustment of circuit components, they are not part of the adjustment software.Written procedures for these adjustments start on page 5–7. If you are using...

Page 163 - Table 5–2: Adjustments Required for Module Replaced; Module Replaced; Table 5–3: Adjustments and Dependencies; Adjustment After Repair

Adjustment Procedures 5–4 TDS 684A, TDS 744A, & TDS 784A Service Manual After the removal and replacement of a module due to electrical failure, youmust either do a complete adjustment or no adjustment at all, depending on themodule replaced. See Table 5–2. Table 5–2: Adjustments Required for Mo...

Page 165 - Requires a TM 500 or TM5000 Series Power Module Mainframe.

Adjustment Procedures 5–6 TDS 684A, TDS 744A, & TDS 784A Service Manual Table 5–4: Test Equipment, Fixtures, and Supplies (Cont.) Item Number andDescription Purpose Example Minimum Requirements 14. Generator, Leveled Sine Wave, High-Frequency 250 MHz to 1 GHz; Variableamplitude from 0.5 V to 4 V...

Page 166 - Adjustment Instructions; accompanying your GPIB card to install and configure that card.; Table 5–5: GPIB Board Configuration; Board Settings; Hardware Installation

Adjustment Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 5–7 Adjustment Instructions The following instructions describe installing the software on your system,setting up the oscilloscope for adjustment, and starting the adjustment of theoscilloscope by the software. 1. Install the pr...

Page 167 - b. The adjustment software will be installed in a directory called; Power on the oscilloscope.; d. Use the keypad to set any address between 0 and 29.; Adjustments

Adjustment Procedures 5–8 TDS 684A, TDS 744A, & TDS 784A Service Manual 2. Install the software to hard disk: a. Install your working disk in a floppy drive and type install. The software will ask you to specify the hard disk on which to install the adjustmentsoftware. It will also prompt you to...

Page 168 - Figure 5–1: Accessing the Protection Switch

Adjustment Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 5–9 d. Follow the instructions as prompted on your computer screen. This will include the actions listed in step 5 shown below. 5. Enable the adjustment constants to be written –when prompted on your computer screen in step 4 ab...

Page 169 - d. To do a complete adjustment as defined on page 5–3, you must also do; Probe Adjustment for the P6139A Probe; Compensate the Probe

Adjustment Procedures 5–10 TDS 684A, TDS 744A, & TDS 784A Service Manual CAUTION. Be sure to disable the NVRAM Protection switch as instructed below to protect the adjustment constants against alteration. a. Locate the two small access holes on the right side of the oscilloscope cabinet near the...

Page 170 - Figure 5–2: Hookup for Probe Compensation; Press AUTOSET. Set the horizontal SCALE to 250

Adjustment Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 5–11 Figure 5–2: Hookup for Probe Compensation a. Hook up test-signal source: Install the optional-accessory probe to CH 1. Connect the probe tip to PROBE COMPENSATION SIGNAL on thefront panel; connect the probe ground to PROBE ...

Page 171 - Figure 5–3: Performing Probe Compensation; Figure 5–4: Proper and Improper Probe Compensation

Adjustment Procedures 5–12 TDS 684A, TDS 744A, & TDS 784A Service Manual Figure 5–3: Performing Probe Compensation 2. Compensate the Probe: a. Locate the probe compensation hole in the side of the probe body. b. Using the probe compensation tool, adjust the probe for best square wave compensatio...

Page 172 - Figure 5–5: Exposing the Inner Probe Tip; Measure Probe Bandwidth

Adjustment Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 5–13 3. Disconnect the hookup: Disconnect the probe from the probe compensator terminals; leave probe installed on CH 1 and leave the oscilloscope controlsetup as is for doing the next part of probe adjustment. EquipmentRequired...

Page 173 - Figure 5–6: Initial Test Hookup

Adjustment Procedures 5–14 TDS 684A, TDS 744A, & TDS 784A Service Manual Digitizing Oscilloscope BNC-Female-to- Female BNC Adapter Leveling Head BNC-to ProbeTip Adapter High Frequency Sine Wave Generator Output Figure 5–6: Initial Test Hookup c. Initialize the oscilloscope: H Press save/recall S...

Page 174 - Adjust the Probe — High

Adjustment Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 5–15 a. Display and measure the test signal: H Monitor the CH 1 Pk-Pk readout while you set the output of thegenerator for a 3.0 V (6 division), 6 MHz reference signal. H Set the horizontal SCALE to 1 ns and set the frequency of...

Page 175 - Figure 5–7: Exposing the Probe Body; precision cable to the input of a tunnel diode pulser.

Adjustment Procedures 5–16 TDS 684A, TDS 744A, & TDS 784A Service Manual a. Access Inner Probe Tip and Adjustment Ports: H The probe tip should be exposed from the procedure Measure ProbeBandwidth. If not, follow the instructions in Figure 5–5 to exposethe probe tip. H Follow the instructions in...

Page 176 - Figure 5–8: Initial Test Hookup

Adjustment Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 5–17 Digitizing Oscilloscope Calibration Generator Tunnel Diode Pulser 10X Attenuator Precision Cable Output Figure 5–8: Initial Test Hookup c. Initialize the oscilloscope: H Press save/recall SETUP. H Press the main-menu button...

Page 177 - Make the adjustments:

Adjustment Procedures 5–18 TDS 684A, TDS 744A, & TDS 784A Service Manual H Press SHIFT; then press ACQUIRE MENU. H Press the main-menu button Mode. Then press the side-menu buttonAverage 16. H Push SET LEVEL TO 50% as required to trigger the signal. H Advance the horizontal SCALE to 5 ns. H Pres...

Page 178 - Figure 5–9: Locations of P6139A Probe Adjustments

Adjustment Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 5–19 LF Comp R1 R2 C1 Not Used Figure 5–9: Locations of P6139A Probe Adjustments H See Figure 5–10 to see what areas on the front corner that thevarious adjustments affect. d. Recheck Probe Bandwidth: H Redo the procedure Adjust...

Page 179 - Figure 5–10: Adjustments versus Front-Corner Response

Adjustment Procedures 5–20 TDS 684A, TDS 744A, & TDS 784A Service Manual 5 ns C1 20 ns R1 10 ns R2 Adjust R1 for best overall match. 1 Adjust R2 and C1 for best matchbetween front corners. 2 Repeat the first two steps as neededdue to interaction between adjustments. 3 Figure 5–10: Adjustments ve...

Page 180 - Display Assembly Adjustment; Procedures in Section 6 to remove the cabinet.; Contrast Adjustment

Adjustment Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 5–21 Display Assembly Adjustment STOP . It is not necessary to do this procedure to perform a complete adjustment. Only use this procedure to adjust the display assembly if it has been repaired orif brightness and contrast have ...

Page 181 - Figure 5–11: Five and Ten Percent Luminance Patches

Adjustment Procedures 5–22 TDS 684A, TDS 744A, & TDS 784A Service Manual 3. Adjust the display brightness H Locate R403 (BRIGHTNESS). It is one of the adjustments on theleft side of the instrument located just ahead of the fan. It is thefourth adjustment from the fan. H Observe the luminance pat...

Page 182 - a. Restore the dip switch to the settings that follow:

Adjustment Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 5–23 H Press the main-menu button EXECUTE; then press the side-menubutton Ok Confirm Run Test. b. Make the contrast adjustment: H Locate R404. It is one of the adjustments on the left side of theinstrument located just ahead of ...

Page 185 - Maintenance; Related Maintenance Procedures

TDS 684A, TDS 744A, & TDS 784A Service Manual 6–1 Maintenance This section contains the information needed to do periodic and correctivemaintenance on the TDS 684A and 7XXA Digitizing Oscilloscopes. Thefollowing subsections are included: H Preparation — Introduction plus general information on p...

Page 186 - Preparation; Static discharge can damage any semiconductor component in this; Handle circuit boards by the edges when possible.; capable of generating a static charge.; Susceptibility to ESD.; Table 6–1 lists the relative susceptibility of various classes; Preventing ESD

Maintenance 6–2 TDS 684A, TDS 744A, & TDS 784A Service Manual H Section 10, Mechanical Parts List, lists all field replaceable modules by partnumber. Preparation CAUTION. Static discharge can damage any semiconductor component in this oscilloscope. Precautions. When performing any service which ...

Page 187 - Table 6–1: Relative Susceptibility to Static-Discharge Damage; Semiconductor Classes

Maintenance TDS 684A, TDS 744A, & TDS 784A Service Manual 6–3 Table 6–1: Relative Susceptibility to Static-Discharge Damage Semiconductor Classes Relative SusceptibilityLevels 1 MOS or CMOS microcircuits or discrete circuits, or linearmicrocircuits with MOS inputs (most sensitive) 1 ECL 2 Schott...

Page 188 - Inspection and Cleaning; that; Inspection — Exterior.; Inspect the outside of the oscilloscope for damage, wear,; General Care

Maintenance 6–4 TDS 684A, TDS 744A, & TDS 784A Service Manual Inspection and Cleaning Inspection and Cleaning describes how to inspect for dirt and damage on, andhow to clean the exterior and interior of the TDS 684A and 7XXA DigitizingOscilloscopes. Inspection and cleaning are done as preventiv...

Page 189 - Table 6–2: External Inspection Check List; Item; Cleaning Procedure — Exterior.; To clean the oscilloscope exterior, do the following:; Inspection — Interior.; To access the inside of the oscilloscope for inspection and

Maintenance TDS 684A, TDS 744A, & TDS 784A Service Manual 6–5 Table 6–2: External Inspection Check List Item Inspect For Repair Action Cabinet, front panel,and cover Cracks, scratches, deformations,damaged hardware or gaskets. Repair or replace defectivemodule. Front-panel knobs Missing, damaged...

Page 190 - Table 6–3: Internal Inspection Check List; Cleaning Procedure — Interior.; To clean the oscilloscope interior, do the following:

Maintenance 6–6 TDS 684A, TDS 744A, & TDS 784A Service Manual CAUTION. To prevent damage from electrical arcing, ensure that circuit boards and components are dry before applying power to the oscilloscope. Table 6–3: Internal Inspection Check List Item Inspect For Repair Action Circuit boards Lo...

Page 193 - Preparation — Please Read; Before doing this or any other procedure in this manual, read the; List of Modules

TDS 684A, TDS 744A, & TDS 784A Service Manual 6–9 Removal and Installation Procedures This subsection contains procedures for removal and installation of all mechani-cal and electrical modules. Any electrical or mechanical module, assembly, orpart listed in Section 10 of this manual is a module....

Page 194 - General Instructions

Removal and Installation Procedures 6–10 TDS 684A, TDS 744A, & TDS 784A Service Manual STOP . READ THESE GENERAL INSTRUCTIONS BEFORE REMOVING A MODULE. First read over the Summary of Procedures that follows to understand how theprocedures are grouped. Then read Equipment Required for a list of t...

Page 195 - Table 6–4: Tools Required for Module Removal

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–11 tool whenever a procedure step instructs you to remove or install a screw unlessa different size screwdriver is specified in that step. All equipment required toremove and reinstall each module is listed in th...

Page 196 - Figure 6–1: External Modules

Removal and Installation Procedures 6–12 TDS 684A, TDS 744A, & TDS 784A Service Manual Line Cord Fuse Cap Handle Trim Ring Front Panel Knobs Front Cover Line Fuse Handle Cap Attenuator Cover Foot Pad Flip Stand Cabinet Rear Cover A12 Front Panel Assembly Foot Display Frame Menu Buttons EMI Gaske...

Page 199 - Access Procedure; a. Find the module to be removed in the module locator diagrams,; found under Procedures for External Modules.

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–15 Access Procedure Begin with this procedure when you have identified a module to be removed forservice and have read General Instructions found earlier in this section. 1. Locate module to be removed: a. Find t...

Page 200 - Procedures for External Modules; tweezers

Removal and Installation Procedures 6–16 TDS 684A, TDS 744A, & TDS 784A Service Manual c. Do, in the order listed, the three procedures A14 D1 Bus and Analog-Power and Digital-Power Cables, A11 Processor/Display Board and TopCover found under Procedures for Outer-Chassis Modules, page 6–29. d. F...

Page 201 - Figure 6–4: Knob Removal; Line Fuse and Line Cord

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–17 When reinstalling the knobs, note there are three sizes. Be sure to reinstall the proper size knob in the proper location. Figure 6–4: Knob Removal 1. Assemble equipment and locate modules to be removed: Have ...

Page 202 - Figure 6–5: Line Fuse and Line Cord Removal; See Rear Cover and Cabinet procedure on page 6–18.; a. Have handy a screwdriver with a size T-20 Torx; tip; EMI Gaskets

Removal and Installation Procedures 6–18 TDS 684A, TDS 744A, & TDS 784A Service Manual 5. Reinstallation: Do in reverse steps 3 and 4 to reinstall the line cord and then the line fuse. Line Fuse Fuse Cap 1 Unplug 2 Rotate 3 Pull Figure 6–5: Line Fuse and Line Cord Removal See Rear Cover and Cabi...

Page 205 - Figure 6–6: Rear Cover and Cabinet Removal

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–21 Figure 6–6: Rear Cover and Cabinet Removal

Page 206 - Attenuator Panel

Removal and Installation Procedures 6–22 TDS 684A, TDS 744A, & TDS 784A Service Manual 1. Assemble equipment and locate modules to be removed: No tools are needed. Locate the modules to be removed in the locator diagram External Modules,Figure 6–1. 2. Orient the oscilloscope: Set the oscilloscop...

Page 207 - a. Have handy a screwdriver with a size T-15 Torx; b. Locate the modules to be removed in the locator diagram External; A12 Front-Panel Assembly

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–23 4. Remove the trim ring: Grasp the trim ring by its top edge and pry it up and lift it forward to snap it off of the front subpanel. If servicing the menubuttons, lift them out of the trim ring. (When reinstal...

Page 208 - Figure 6–8: A12 Front-Panel Assembly Removal; front-panel buttons are to be serviced, do the following substeps:

Removal and Installation Procedures 6–24 TDS 684A, TDS 744A, & TDS 784A Service Manual Front-Panel Assembly Back of Front–Panel Assembly Ground Ground P2 P2 QuickDisconnectStud Mount W76 CablePowerAssembly P3 Torxdrive Screw T–15 Figure 6–8: A12 Front-Panel Assembly Removal 4. Further disassembl...

Page 209 - Figure 6–9: Disassembly of Front-Panel Assembly; Assemble equipment and locate modules to be removed: Have handy a; Display-Frame Assembly

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–25 c. Now hand disassemble the front-panel assembly components usingFigure 6–9 as a guide. Reverse procedure to reassemble, using the sameFigure 6–9 as a guide. Figure 6–9: Disassembly of Front-Panel Assembly 5. ...

Page 210 - Cabinet Modules

Removal and Installation Procedures 6–26 TDS 684A, TDS 744A, & TDS 784A Service Manual 2. Orient the oscilloscope: Set the oscilloscope so its bottom is down on the work surface and its front is facing you. 3. Remove the display-frame assembly: a. Do the procedure Front Cover, Trim Ring, Menu Bu...

Page 212 - Figure 6–10: Cabinet Modules Removal

Removal and Installation Procedures 6–28 TDS 684A, TDS 744A, & TDS 784A Service Manual Handle Removal Flip StandRemoval Foot Removal Handle Cap Removal Push down to flex handle and flatten against cabinet; then pull it out. Figure 6–10: Cabinet Modules Removal

Page 213 - Procedures for Outer-Chassis Modules; Assemble equipment and locate module to be removed: Have handy a; Fan

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–29 Procedures for Outer-Chassis Modules You should have completed the Access Procedure before doing any procedure inthis collection. The procedures found here, listed in order presented, follow. H Fan H A14 D1 Bu...

Page 215 - a. Using a screwdriver with size T-15 Torx; tip, remove the two screws; Figure 6–12: Remove Circuit Board Assembly From Oscilloscope; inch nutdriver, remove the four lock connectors (number 3 in; A23 SerPar Board —

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–31 1. Remove circuit board assembly: a. Using a screwdriver with size T-15 Torx R tip, remove the two screws (number 4 in Figure 6–12) securing the rear plate of the circuit boardassembly. b. Disconnect the cable...

Page 216 - Figure 6–13: Remove Circuit Board From Assembly; power-up short diagnostics procedure described on page 6–57.; A29 Video Trigger Board

Removal and Installation Procedures 6–32 TDS 684A, TDS 744A, & TDS 784A Service Manual b. Separate the circuit board with attached cable (number 1), from the rear plate with attached brackets (number 2). 1 2 3 Figure 6–13: Remove Circuit Board From Assembly 3. Replace circuit board: Equipment Re...

Page 217 - b. Slide back and lift up the Video Trigger circuit board (see Figure

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–33 b. Locate the modules to be removed in the locator diagram Outer-Chassis Modules, Figure 6–2, page 6–13. See also the A29 Video Trigger Boardon Figure 6–15, page 6–35. c. Do the procedures A14 D1 Bus and Analo...

Page 218 - Figure 6–14: Circuit Board Installed

Removal and Installation Procedures 6–34 TDS 684A, TDS 744A, & TDS 784A Service Manual Coax Cable Figure 6–14: Circuit Board Installed

Page 219 - Figure 6–15: Circuit Board Removal; of each step to reinstall the A29 Video Trigger Board.

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–35 1 2 3 To J1500 Coax Cable Figure 6–15: Circuit Board Removal 4. Reinstallation: a. Do, in reverse order, steps a through e. Reverse the removal instructions of each step to reinstall the A29 Video Trigger Boar...

Page 220 - procedure A29 Video Trigger Board.; A11 Processor/Display

Removal and Installation Procedures 6–36 TDS 684A, TDS 744A, & TDS 784A Service Manual b. See the procedures A14 D1 Bus and Analog-Power and Digital-Power Cables (page 6–29), A23 SerPar Board (page 6–31) and Rear Cover andCabinet (page 6–18) to complete reassembly of the oscilloscope. c. To ensu...

Page 221 - Figure 6–16: A11 Processor/Display Removal; Assemble equipment and locate modules to be removed:; Top Cover and Board

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–37 installed, A29 Video Trigger Board, and Rear Cover and Cabinet(page 6–18) to complete reassembly of the oscilloscope. J62 J38 J35 J51 J37 J2 J5 J20 To J5 To J37 To J51 To J2 J2 J37 J51 J5 J38 J38 To J38 To J20...

Page 222 - Figure 6–17: Board Bracket Removal

Removal and Installation Procedures 6–38 TDS 684A, TDS 744A, & TDS 784A Service Manual b. Locate the modules to be removed in the locator diagram Outer-Chassis Modules, Figure 6–2, page 6–13. c. Do the procedures A14 D1 Bus and Analog-Power and Digital-PowerCables (page 6–29), A23 SerPar Board (...

Page 223 - b. Working from the rear panel and using the; inch nut driver, unscrew; b. Locate the modules to be removed, including those listed under; A10 Acquisition Board

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–39 H A11 Processor/Display Board (page 6–36) H If option 05 is installed, A29 Video Trigger Board (page 6–32) H A14 D1 Bus and Analog-Power and Digital-Power Cables(page 6–29) H A23 SerPar Board (page 6–31) H Fro...

Page 224 - d. Remove the five front-panel screws that attach the frame to the

Removal and Installation Procedures 6–40 TDS 684A, TDS 744A, & TDS 784A Service Manual d. Do the procedure Front Cover, Trim Ring, Menu Buttons, and Attenuator Panel (page 6–22) 2. Orient the oscilloscope: Set the oscilloscope so its top is down on the work surface and its front is facing you. 3...

Page 225 - Figure 6–18: A10 Acquisition Board Removal

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–41 MAIN TRIGGER OUTPUT DELAYEDTRIGGER OUTPUT AUX TRIGGER INPUT SIGNAL OUTPUT J1100 J1201 J1550 J1000 J1001 J1500 Six Securing Screws Five Securing Screws Analog Power Cable Digital Power Cable A14 D1 Bus Figure 6...

Page 226 - a. Have handy a screwdriver with a small Phillips head.; surface and its front is facing you.; Floppy Disk

Removal and Installation Procedures 6–42 TDS 684A, TDS 744A, & TDS 784A Service Manual 1. Assemble equipment and locate modules to be removed: a. Have handy a screwdriver with a small Phillips head. b. Locate the modules to be removed, including those listed under Additional Modules Removed in t...

Page 227 - Figure 6–19: Floppy Disk Removal

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–43 J38 Figure 6–19: Floppy Disk Removal 5. Reinstallation: Do, in reverse order, substeps 4b then 4a to reinstall the floppy disk. Then see the following procedures, in the order listed, tocomplete reassembly of ...

Page 228 - Install the front cover if it’s not already installed.; b. Unplug the video cable at J51 of the processor/display board.; Rear Chassis

Removal and Installation Procedures 6–44 TDS 684A, TDS 744A, & TDS 784A Service Manual 1. Assemble equipment and locate modules to be removed: a. Have handy a screwdriver with a size T-15 Torx R tip (Items 1 and 2). b. Locate the modules to be removed, including those listed under Additional Mod...

Page 229 - Figure 6–20: Rear Chassis Removal

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–45 CH3 OUT to J1201 AUXILIARY TRIGGER to J1550 MAIN TRIGGER to J1000 DELAY TRIGGER to J1001 EMI Gaskets Figure 6–20: Rear Chassis Removal

Page 230 - Procedures for Inner-Chassis Modules; A16 Low Voltage Power Supply; a. Working from the rear of the oscilloscope, remove the two screws; If option 05 is installed, A29 Video Trigger Board (page 6–32); A16 Low Voltage Power

Removal and Installation Procedures 6–46 TDS 684A, TDS 744A, & TDS 784A Service Manual Procedures for Inner-Chassis Modules You should have completed the Access Procedure (page 6–15) before doing anyof the procedures for the Inner-Chassis modules. The procedures are presented inthe following ord...

Page 231 - Figure 6–21: A16 Low Voltage Power Supply Removal; A30 Display Assembly

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–47 H A14 D1 Bus and Analog-Power and Digital-Power Cables (page 6–29) H Rear Cover and Cabinet (page 6–18) Rotate the edge of the boardupward as indicated to clear the lip of the main chassis when lifting this bo...

Page 233 - Figure 6–22: Display Assembly Removal; Remove the display supply board: Use Figure 6–23 as a guide.

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–49 e. Be sure you have read the WARNING on display tube handling andstorage found at the start of this display tube removal procedure. Thenpull the display tube out through the front subpanel to complete removal....

Page 234 - Figure 6–23: Display Driver Board Removal; display tube if removed.

Removal and Installation Procedures 6–50 TDS 684A, TDS 744A, & TDS 784A Service Manual b. Grasp the display driver board. Work from the front and top to tilt the board so its right edge is up and its left side is down and lift it out of thetop of the oscilloscope’s main chassis. Move circuit boa...

Page 235 - b. See the procedure A30 Display Assembly and Supply Fuse (page 6–47); Front Subpanel

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–51 H Top Cover and Board Brackets (top cover only) on page 6–37 H A11 Processor/Display Board (page 6–36) H If option 05 is installed, A29 Video Trigger Board (page 6–32) H A14 D1 Bus and Analog-Power and Digital...

Page 236 - Figure 6–24: Front Subpanel Removal; Main Chassis

Removal and Installation Procedures 6–52 TDS 684A, TDS 744A, & TDS 784A Service Manual H A14 D1 Bus and Analog-Power and Digital-Power Cables(page 6–29) H Front Cover, Trim Ring, Menu Buttons, and Attenuator Panel(page 6–22) H Rear Cover and Cabinet (page 6–18) Figure 6–24: Front Subpanel Remova...

Page 237 - Disassembly for Cleaning

Removal and Installation Procedures TDS 684A, TDS 744A, & TDS 784A Service Manual 6–53 Disassembly for Cleaning This procedure is for disassembly of the Digitizing Oscilloscopes into itsindividual modules so they can be cleaned. For the cleaning instructions, seeInspection and Cleaning, which be...

Page 241 - Troubleshooting; Diagnostics; b. Repeatedly press the main-menu button System until Diag/Err is

TDS 684A, TDS 744A, & TDS 784A Service Manual 6–57 Troubleshooting This subsection contains information and procedures designed to help you isolatefaulty modules in the oscilloscope. If a module needs to be replaced, follow theRemoval and Installation Procedures located in this section. Diagnost...

Page 242 - Firmware Updates; Figure 6–25: Accessing the Protection Switch

Troubleshooting 6–58 TDS 684A, TDS 744A, & TDS 784A Service Manual Firmware Updates Digitizing Oscilloscopes firmware updates are easy to do. Simply install thefirmware disks on your PC and follow the instructions in the README filelocated on the first disk. NOTE . You must set the Protection sw...

Page 243 - Figure 6–26: Primary Troubleshooting Procedure

Troubleshooting TDS 684A, TDS 744A, & TDS 784A Service Manual 6–59 Replace the A10 Acquisition module Perform the A16 Low Voltage Power Supply Module Isolation troubleshooting procedure. Does the oscilloscope power on, all the diagnostics pass, but sometime later powers down on its own? Yes No Y...

Page 245 - Figure 6–27: Module Isolation Troubleshooting Procedure

Troubleshooting TDS 684A, TDS 744A, & TDS 784A Service Manual 6–61 Done. No Yes Does the display report any errors? Are any failures reported? The oscilloscope is ok. Select the extended diagnostics menu and run all the test suites (the discussion of the Diagnostics on page 6–57 explains how to ...

Page 247 - Figure 6–29: Power Supply Voltage Measurement Locations

Troubleshooting TDS 684A, TDS 744A, & TDS 784A Service Manual 6–63 Table 6–5: Normal Supply Voltages (Measured on J26 and J27 on the A11 DRAMProcessor/Display Module) Supply Lower Limit Upper Limit Ground (J26 or J27 pin 15) +5.1 VA (J27 pin 5) +5.0 V +5.2 V +5.1 VB (J27 pin 17) +5.0 V +5.2 V +2...

Page 248 - Figure 6–30: Color Display Troubleshooting Procedure

Troubleshooting 6–64 TDS 684A, TDS 744A, & TDS 784A Service Manual No Yes Replace the A11 DRAM Processor/Display module. Is the display legible but the horizontal and/or vertical sync do not look ok? Do J18 pins 1 and 2 on the A11 DRAM Processor/Display module (see Figure 6–38) have signals simi...

Page 249 - Figure 6–31: Horizontal and Vertical Sync Signals – Color Display

Troubleshooting TDS 684A, TDS 744A, & TDS 784A Service Manual 6–65 J18 pin 1 (Horizontal Sync) J18 pin 2 (Vertical Sync) Figure 6–31: Horizontal and Vertical Sync Signals – Color Display J62 pin 1 (Video) White Level Black Levels Blanking Levels Figure 6–32: A Video Signal with White, Black, and...

Page 250 - Figure 6–33: Processor/Acquisition Troubleshooting Procedure

Troubleshooting 6–66 TDS 684A, TDS 744A, & TDS 784A Service Manual Replace the A11 DRAM Processor/Display module. Select the extended diagnostics menu and run all the test suites (the discussion of the Diagnostics on page 6–57 explains how to do this). Do the Processor/Acq tests pass now? No Yes...

Page 251 - Figure 6–34: Processor/Front Panel Troubleshooting Procedure

Troubleshooting TDS 684A, TDS 744A, & TDS 784A Service Manual 6–67 This procedure helps you determine if the A11 DRAM Processor/Display or the A12 Front Panel module is bad. Perform the Low Voltage Power Supply troubleshooting procedure. Probe J26 and J27 but DO NOT REMOVE the cables from the co...

Page 252 - Figure 6–35: Attenuator/Acquisition Troubleshooting Procedure

Troubleshooting 6–68 TDS 684A, TDS 744A, & TDS 784A Service Manual Do all the channels display defective waveforms? Attach a probe to the PROBE COMPENSATION signal located on the front of the oscilloscope. Connect the probe to a channel’s BNC on the front, select the channel and view the output ...

Page 256 - Figure 6–39: A10 Acquisition Module (View of Lower Right Corner)

Troubleshooting 6–72 TDS 684A, TDS 744A, & TDS 784A Service Manual Pin 11 Pin 5 Pin 7 Pin 9 U604 U1001 U1540 Figure 6–39: A10 Acquisition Module (View of Lower Right Corner)

Page 258 - Options and Accessories; Options; Tektronix will ship the options shown in Table 7–1:; Label

TDS 684A, TDS 744A, & TDS 784A Service Manual 7–1 Options and Accessories This section describes the various options as well as the standard and optionalaccessories that are available for the TDS 684A and 7XXA Oscilloscope. Options Tektronix will ship the options shown in Table 7–1: Table 7–1: O...

Page 260 - Standard Accessories; Table 7–2: Standard Accessories; Accessory

Options and Accessories TDS 684A, TDS 744A, & TDS 784A Service Manual 7–3 Table 7–1: Options (Cont.) Description Label Option # 95 Calibration Data Report 96 Calibration Certificate Certificate of Calibration which states this instrument meets orexceeds all warranted specifications and has been ...

Page 261 - Optional Accessories; You can also order the optional accessories listed in Table 7–3.; Table 7–3: Optional Accessories; Provides 100X, when ordered with Option 25.; Accessory Probes

Options and Accessories 7–4 TDS 684A, TDS 744A, & TDS 784A Service Manual Optional Accessories You can also order the optional accessories listed in Table 7–3. Table 7–3: Optional Accessories Accessory Part Number Service Manual 070-8992-xx Plotter (GPIB and Centronics Standard) HC100 Oscillosco...

Page 262 - Table 7–4: Accessory Software; Software; Accessory Software

Options and Accessories TDS 684A, TDS 744A, & TDS 784A Service Manual 7–5 H AM 503S — DC/AC Current probe system, AC/DC. Uses A6302 CurrentProbe. H AM 503S Option 03: DC/AC Current probe system, AC/DC. Uses A6303Current Probe. H P6021 AC Current probe. 120 Hz to 60 MHz. H P6022 AC Current probe....

Page 265 - Electrical Parts List

TDS 684A, TDS 744A, & TDS 784A Service Manual 8–1 Electrical Parts List The modules that make up this instrument are often a combination of mechanicaland electrical subparts. Therefore, all replaceable modules are listed in Section 10, Mechanical Parts List. Refer to that section for part number...

Page 268 - Diagrams; Symbols

TDS 684A, TDS 744A, & TDS 784A Service Manual 9–1 Diagrams This contains the block diagram and the interconnection diagram for theTDS 684A and 7XXA Digitizing Oscilloscopes. Symbols Graphic symbols and class designation letters are based on ANSI StandardY32.2–1975. Abbreviations are based on ANS...

Page 269 - Figure 9–1: Interconnections

Diagrams 9–2 TDS 684A, TDS 744A, & TDS 784A Service Manual Flex A12 FrontPanelBoard A10 AcquisitionBoard Front Panel Knobs CH 1 CH 2 CH 3 CH 4 Menu Switches A18 Main ConverterControl Board A19 Power FactorControl Board A17 Main LV PowerSupply Board Filter A29 VideoTriggerBoard A J1153 J102 J101 ...

Page 271 - Figure 9–2: Block Diagram

Diagrams 9–4 TDS 684A, TDS 744A, & TDS 784A Service Manual A14 D1 Bus FloppyDriver 100 A12 Front Panel A10 Acquisition CH 1 CH 2 CH 3 CH 4 Menu Switches A18 Main Converter Control A19 Power Factor Control A17 Main LV Power Supply Filter A29 VideoTrigger J1 10 Attenuator 100 (Option 05) Triggers ...

Page 275 - Mechanical Parts List; Parts Ordering Information; Module Repair and Return.; Module Servicing

TDS 684A, TDS 744A, & TDS 784A Service Manual 10–1 Mechanical Parts List This section contains a list of the replaceable modules for the oscilloscope. Usethis list to identify and order replacement parts. Parts Ordering Information Replacement parts are available through your local Tektronix fie...

Page 276 - Using the Replaceable Parts List; Parts List Column Descriptions; Column; Abbreviations

Mechanical Parts List 10–2 TDS 684A, TDS 744A, & TDS 784A Service Manual Using the Replaceable Parts List This section contains a list of the mechanical and/or electrical components thatare replaceable for the oscilloscope. Use this list to identify and order replace-ment parts. The following ta...

Page 277 - Manufacturers Cross Index; Manufacturer

Mechanical Parts List TDS 684A, TDS 744A, & TDS 784A Service Manual 10–3 Manufacturers Cross Index Mfr.Code Manufacturer Address City, State, Zip Code S3109 FELLER 72 VERONICA AVEUNIT 4 SUMMERSET NJ 08873 TK0IK MODERN METALS UNIT A/K, 5/F GOLD KING IND.BLDG NO. 35–41 TAI LIN ROAD KWAI–CHUNG N.T....

Page 278 - Address

Mechanical Parts List 10–4 TDS 684A, TDS 744A, & TDS 784A Service Manual Manufacturers Cross Index (Cont.) Mfr.Code City, State, Zip Code Address Manufacturer 34416 PARSONS MFG CORP 1055 OBRIAN DR MENLO PARK CA 94025–1408 5Y400 TRIAX METAL PRODUCTS INCDIV OF BEAVERTON PARTS MFG CO 1800 NW 216TH ...

Page 280 - Replaceable Parts List

Mechanical Parts List 10–6 TDS 684A, TDS 744A, & TDS 784A Service Manual Replaceable Parts List Fig. &IndexNumber Tektronix PartNumber Serial No.Effective Serial No.Discont’d Qty Name & Description Mfr.Code Mfr. Part Number 1–1 200–3695–02 1 COVER,REAR:REAR COSMETIC COVER TK1163 200–3695...

Page 281 - Figure 10–1: External Modules

Mechanical Parts List TDS 684A, TDS 744A, & TDS 784A Service Manual 10–7 A12 1 2 3 4 5 6 7 8 9 10 11 12 13 13 14 15 16 17 18 19 20 21 22 23 Figure 10–1: External Modules

Page 289 - Figure 10–6: Floppy Disk

Mechanical Parts List TDS 684A, TDS 744A, & TDS 784A Service Manual 10–15 1 2 3 4 5 6 Figure 10–6: Floppy Disk

Page 290 - Figure 10–7: Accessories

Mechanical Parts List 10–16 TDS 684A, TDS 744A, & TDS 784A Service Manual Replaceable Parts List Fig. &IndexNumber Tektronix PartNumber Serial No.Effective Serial No.Discont’d Qty Name & Description Mfr.Code Mfr. Part Number STANDARD ACCESSORIES 7–1 161–0104–05 1 CA ASSY,PWR:3,1.0MM SQ,2...