Service Manual TDS 684A, TDS 744A, & TDS 784A Digitizing Oscilloscope 070-8992-03 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 the Safety Summary prior to performing service. Please check for change information at the rear of this manual.
Copyright Tektronix, Inc. 1994, 1995. All rights reserved. Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes that in all previously published material. Specifications and price change privileges reserved. Printed in the U.S.A. Tektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070–1000 TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
WARRANTY Tektronix warrants that this product will be free from defects in materials and workmanship for a period of three (3) years from the date of shipment. If any such product proves defective during this warranty period, Tektronix, at its option, either will repair the defective product without charge for parts and labor, or will provide a replacement in exchange for the defective product.
Table of Contents General Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix xiii xv xix Product Description . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–15 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TDS 684A Test Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TDS 7XXA Test Record . . . . . . . . . . .
Table of Contents List of Figures Figure 2–1: Map of Display Functions . . . . . . . . . . . . . . . . . . . . . . . . . 2–8 Figure 4–1: Map of Display Functions . . . . . . . . . . . . . . . . . . . . . . . . . Figure 4–2: Verifying Adjustments and Signal-Path Compensation . Figure 4–3: Universal Test Hookup for Functional Tests . . . . . . . . . . Figure 4–4: Measurement of DC Offset Accuracy at Zero Setting . . . Figure 4–5: Initial Test Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents iv Figure 4–31: 60 Hz Rejection Test Setup Signal . . . . . . . . . . . . . . . . . . Figure 4–32: Subsequent 60 Hz Rejection Test Hookup . . . . . . . . . . . Figure 4–33: 60 Hz Rejection Test Result – TDS 684A Shown . . . . . . Figure 4–34: Line Count Accuracy Test Hookup . . . . . . . . . . . . . . . . . Figure 4–35: Line Count Accuracy Test Setup Waveform – TDS 684A Shown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents Figure 6–16: A11 Processor/Display Removal . . . . . . . . . . . . . . . . . . . Figure 6–17: Board Bracket Removal . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 6–18: A10 Acquisition Board Removal . . . . . . . . . . . . . . . . . . . Figure 6–19: Floppy Disk Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 6–20: Rear Chassis Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 6–21: A16 Low Voltage Power Supply Removal . . . . . . . . .
Table of Contents vi TDS 684A, TDS 744A, & TDS 784A Service Manual
Table of Contents List of Tables Table 1–1: Key Features of the TDS 684A and 7XXA Oscilloscopes Table 1–2: Record Length vs. Divisions per Record, Samples per Division and Sec/Div Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1–3: Nominal Traits — Signal Acquisition System . . . . . . . . . . Table 1–4: Nominal Traits — Time Base System . . . . . . . . . . . . . . . . Table 1–5: Nominal Traits — Triggering System . . . . . . . . . . . . . . . .
Table of Contents viii Table 6–2: External Inspection Check List . . . . . . . . . . . . . . . . . . . . . Table 6–3: Internal Inspection Check List . . . . . . . . . . . . . . . . . . . . . . Table 6–4: Tools Required for Module Removal . . . . . . . . . . . . . . . . . Table 6–5: Normal Supply Voltages (Measured on J26 and J27 on the A11 DRAM Processor/Display Module) . . . . . . . . . . . . . . . . . . Table 6–6: No-Load Supply Voltages (Measured on J5 and J6 on the A17 Main LV Power Supply Module) . .
General Safety Summary Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it. Only qualified personnel should perform service procedures. Injury Precautions Use Proper Power Cord To avoid fire hazard, use only the power cord specified for this product. Avoid Electric Overload To avoid electric shock or fire hazard, do not apply a voltage to a terminal that is outside the range specified for that terminal.
General Safety Summary Use Proper Voltage Setting Provide Proper Ventilation Do Not Operate With Suspected Failures Do Not Immerse in Liquids Before applying power, ensure that the line selector is in the proper position for the power source being used. To prevent product overheating, provide proper ventilation. If you suspect there is damage to this product, have it inspected by qualified service personnel. Clean the probe using only a damp cloth. Refer to cleaning instructions.
General Safety Summary Symbols on the Product 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 Certified Power Cords CSA Certification includes the products and power cords appropriate for use in the North America power network. All other power cords supplied are approved for the country of use.
General Safety Summary xii TDS 684A, TDS 744A, & TDS 784A Service Manual
Service Safety Summary Only qualified personnel should perform service procedures. Read this Service Safety Summary and the General Safety Summary before performing any service procedures. Do Not Service Alone Do not perform internal service or adjustments of this product unless another person capable of rendering first aid and resuscitation is present. Disconnect Power To avoid electric shock, disconnect the main power by means of the power cord or, if provided, the power switch.
Service Safety Summary xiv TDS 684A, TDS 744A, & TDS 784A Service Manual
Preface This preface contains information needed to properly use this manual to service the TDS 684A and 7XXA Digitizing Oscilloscopes, as well as general information critical to safe and effective servicing of this oscilloscope. Manual Structure This manual is divided into sections, such as Specification and Theory of Operation. Further, it is divided into subsections, such as Product Description and Removal and Installation Procedures.
Preface H Diagrams contains a block diagram and an interconnection diagram useful for isolating failed modules. H Mechanical Parts List includes a table of all replaceable modules, their descriptions, and their Tektronix part numbers. Manual Conventions This manual uses certain conventions which you should become familiar with before doing service. Modules Throughout this manual, any replaceable component, assembly, or part of these Digitizing Oscilloscopes is referred to generically as a module.
Preface TDS Family (400, 5XXA, 6XXA, and 7XXA) Programmer Manual (Tektronix part number 070-8709-XX) contains information for programmed operation via the GPIB interface. Included is the complete command set, setup information, and programming examples. TDS 684A, TDS 744A, & 784A Technical Reference (Tektronix part number 070-8990-XX) contains performance verification procedures and specifications.
Preface xviii TDS 684A, TDS 744A, & TDS 784A Service Manual
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 of the TDS 684A and 7XXA Digitizing Oscilloscopes. (Examples of such information are procedures for checking performance and for readjustment.) Further, it contains all information for corrective maintenance down to the module level.
Introduction 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 Test Data Report. This certificate provides traceability to the National Institute of Standards and Technology (NIST). It certifies procedures used to calibrate the oscilloscope comply with U. S. Military Standard 45662A. At-Depot Service.
Introduction 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 following tasks before you attempt service: H Be sure you are a qualified service person. H Read the Safety Summary found at the beginning of this manual. H Read Service Strategy in this section and Supplying Operating Power in section 2. When using this manual for servicing, be sure to heed all warnings, cautions, and notes.
Introduction xxii TDS 684A, TDS 744A, & TDS 784A Service Manual
Specifications This section begins with a general description of the traits of the TDS 684A and 7XXA Digitizing Oscilloscopes. Three sections follow, one for each of three classes of traits: nominal traits, warranted characteristics, and typical characteristics. Product Description The TDS 684A and 7XXA Digitizing Oscilloscopes are portable, four-channel instruments suitable for use in a variety of test and measurement applications and systems. Table 1–1 lists key features.
Specifications User Interface Use a combination of front-panel buttons, knobs, and on-screen menus to control the many functions of the oscilloscope. The front-panel controls are grouped according to function: vertical, horizontal, trigger, and special. Set a function you adjust often, such as vertical positioning or the time base setting, directly by its own front-panel knob. Set a function you change less often, such as vertical coupling or horizontal mode, indirectly using a selected menu.
Specifications Besides these channels, up to three math waveforms and four reference waveforms are available for display. (A math waveform results when you specify dual waveform operations, such as add, on any two channels. A reference waveform results when you save a waveform in a reference memory.) Horizontal System There are three horizontal display modes: main only, main intensified, and delayed only. You can select among various horizontal record length settings.
Specifications The delayed display (or the intensified zone) may also be delayed by a selected number 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 plus an amount of time. Trigger System The triggering system supports a varied set of features for triggering the signal-acquisition system.
Specifications H Select the mode for interpolation (linear or sin (x)/x). This can increase the apparent sample rate on the waveform when the maximum real-time rate is exceeded. H Use sample, envelope, and average modes to acquire signals. With the TDS 7XXA, also use high-resolution and peak-detect modes. H Set the acquisition to stop after a single acquisition (or sequence of acquisitions if acquiring in average or envelope modes) or after a limit condition has been met.
Specifications with respect to the trigger point (event) of the acquisition. The cursors can also control the portion of the waveform on which automatic measurements are made. For time measurements, units can be either seconds or hertz (for 1/time). With the video trigger option installed (Option 05), you can measure the video line number using the vertical cursors. You can measure IRE amplitude (NTSC) using the horizontal cursors with or without the video trigger option installed.
Specifications 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 to a variety of graphic printers and plotters from the TDS front panel, providing hard copies without requiring you to put the TDS into a system-controller environment. You can make hardcopies in a variety of popular output formats, such as PCX, TIFF, BMP, RLE, EPS, Interleaf, and EPS mono or color.
Specifications 1–8 TDS 684A, TDS 744A, & TDS 784A Service Manual
Nominal Traits This section contains a collection of tables that list the various nominal traits that describe the TDS 684A and 7XXA oscilloscopes. Electrical and mechanical traits are included. Nominal traits are described using simple statements of fact such as “Four, all identical” for the trait “Input Channels, Number of,” rather than in terms of limits that are performance requirements.
Nominal Traits Table 1–4: Nominal Traits — Time Base System Name Description Range, Sample-Rate1,3 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 channel to 1 G Sample/sec when acquiring 2 channels, or to 500 MSamples/sec when acquiring 3 or 4 channels TDS 784A: 5 Samples/sec to 4 GSamples/sec when acquiring 1 channel to 2 G Sample/sec when acquiring 2 channels, or to 1 GSamples/sec when acquiring 3 or 4 channels Rang
Nominal Traits Table 1–5: Nominal Traits — Triggering System (Cont.) Name Description Ranges, Setup and Hold for TimeSetup/Hold Violation Trigger Feature Min to max Setup Time –100 ns to 100 ns Hold Time –1 ns to 100 ns Setup + Hold Time 2 ns For Setup Time, positive numbers mean a data transition before the clock edge and negative means a transition after the clock edge.
Nominal Traits 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) Interface, Centronics Centronics interface complies with Centronics interface standard C332-44 Feb 1977, REV A Interface, Video VGA video output with levels that comply with EIA RS 343A standard.
Nominal Traits 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 plastic laminate; circuit boards constructed of glass laminate. Cabinet is aluminum and is clad in Tektronix Blue vinyl material. Finish Type Tektronix Blue vinyl-clad aluminum cabinet Weight Standard Digitizing Oscilloscope 14.
Nominal Traits 1–14 TDS 684A, TDS 744A, & TDS 784A Service Manual
Warranted Characteristics This section lists the various warranted characteristics that describe the TDS 684A and 7XXA Digitizing Oscilloscopes. Electrical and environmental characteristics are included. Warranted characteristics are described in terms of quantifiable performance limits which are warranted. NOTE. In these tables, those warranted characteristics that are checked in the procedure Performance Verification appear in boldface type under the column Name.
Warranted Characteristics 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.
Warranted Characteristics Table 1–10: Warranted Characteristics — Signal Acquisition System (Cont.) Name Description Analog Bandwidth, DC-1M Coupled with P6139A Probe and Bandwidth selection is FULL Volts/Div as Read Out on 684A Bandwidth2 Screen 744A Bandwidth2 784A Bandwidth2 10 mV/div – 100 V/div 500 MHz 500 MHz 500 MHz 100 mV/div – 10 V/div 500 MHz 500 MHz 500 MHz 50 mV/div – 99.5 mV/div 500 MHz 500 MHz 500 MHz 20 mV/div – 49.8 mV/div 500 MHz 500 MHz 500 MHz 10 mV/div – 19.
Warranted Characteristics Table 1–12: Warranted Characteristics — Triggering System Name Description Sensitivity, Edge-Type Trigger, Coupling set to “DC”1 Trigger Source Sensitivity Any Channel TDS 684A: 0.35 division from DC to 50 MHz, increasing to 1 division at 1 GHz TDS 7XXA: 0.
Warranted Characteristics 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 selected as the trigger source for the main and/or delayed trigger systems. It is not available when a channel other than CH3 is the source for the Video Trigger when Option 05 is installed.
Warranted Characteristics Table 1–14: Warranted Characteristics — Environmental (Cont.) Name Description Susceptibility1, 2 Meets or exceeds the EMC requirements of the following standards: EN 50082–1 European Community Requirements IEC 801-2 Electrostatic Discharge IEC 801-3 Radiated Susceptibility IEC 801-4 Fast Transients IEC 801-5 AC Surge Third Party Certification Conforms to and is certified where appropriate to: UL 1244 CSA–C22.2 No.
Typical Characteristics This subsection contains tables that list the various typical characteristics which describe the TDS 684A and 7XXA Digitizing Oscilloscopes. Typical characteristics are described in terms of typical or average performance. Typical characteristics are not warranted.
Typical Characteristics Table 1–15: Typical Characteristics — Signal Acquisition System (Cont.) Name Description Effective Bits — TDS 684A Input Frequency Effective Bits The chart on the right gives the typical effective bits for a 9-division p-p sine-wave input, 50 mV/div, 10 ns/div (5 GS/s), with a record length of 1000 points: 98 MHz 6.3 bits 245 MHz 6.0 bits 490 MHz 5.5 bits 990 MHz 5.
Typical Characteristics Table 1–16: Typical Characteristics — Triggering System Name Description Accuracy, Trigger Level or Threshold, DC Coupled (for signals having rise and fall times ≥ 20 ns) Trigger Source Accuracy Any Channel ±((2% × | Setting – Net Offset |) + (0.3 div × Volts/div Setting ) + Offset Accuracy) Auxiliary Not calibrated or specified Input, Auxiliary Trigger The input resistance is ≥1.5 kW; the maximum safe input voltage is ±20 V (DC + peak AC).
Typical Characteristics Table 1–16: Typical Characteristics — Triggering System (Cont.
Typical Characteristics Table 1–16: Typical Characteristics — Triggering System (Cont.) Name Description 6 The minimum signal levels required for stable pulse width or glitch triggering of an acquisition. Also, see the footnote for Sensitivity, Edge-Type Trigger, DC Coupled in this table. (Stable counting of events is counting that misses no events.) 7 For Logic, time between channels refers to the length of time a logic state derived from more than one channel must exist to be recognized.
Typical Characteristics 1–26 TDS 684A, TDS 744A, & TDS 784A Service Manual
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-phase power source. It has a three-wire power cord and two-pole, three-terminal grounding type plug. The voltage to ground (earth) from either pole of the power source must not exceed the maximum rated operating voltage, 250 volts.
Installation 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 Configuration Operating Voltage 2–2 Normal Usage Option Number North America 125 V Standard Europe 230 V A1 United Kingdom 230 V A2 Australia 230 V A3 North America 230 V A4 Switzerland 230 V A5 This oscilloscope operates with any line voltage
Installation Memory Backup Power Memory modules with on-board batteries allow the TDS 684A and 7XXA Digitizing Oscilloscopes to retain some types of data upon loss of the AC power source. The stored adjustment constants, saved front-panel settings, current front-panel settings (instrument status), and waveforms saved in memory are retained. The on-board batteries of the memory modules have a shelf life of about five years.
Installation continue. See Section 6, Maintenance, for information on diagnostics and fault isolation. Power Off CAUTION. DO NOT power off the oscilloscope when either running a signal path compensation or when doing any of the adjustments described in Section 5, Adjustment Procedures. To do so might result in the loss of internally stored adjustment constants. In general, do not power off the instrument when doing operations that affect the data types listed in Table 1–1.
Installation Seal the shipping carton with an industrial stapler or strapping tape. Mark the address of the Tektronix Service Center and also your own return address on the shipping carton in two prominent locations. Installed Options Your instrument may be equipped with one or more instrument options. Except for the line-cord options described by Table 2–2 (on page 2–2 of this section), all options and optional accessories are listed and described in Section 7, Options.
Installation 2–6 TDS 684A, TDS 744A, & TDS 784A Service Manual
Operating Instructions Before doing service, read the following operating instructions. These instructions are at the level appropriate for servicing these Digitizing Oscilloscopes. The User Manual contains more complete operating instructions. Additional instructions are integrated into the service procedures found in later sections of this manual.
Operating Instructions Position of waveform record relative to the screen and display General purpose knob readout Brief status information Side menu area. Readouts for measurements move here when CLEAR MENU is pressed. Graticule and waveforms Waveform reference symbols shows ground levels and waveform sources Vertical scale, horizontal scale, and trigger level readouts Pop-up menu Main menu display area. Readouts in lower graticule area move here when CLEAR MENU is pressed.
Operating Instructions How to Set Functions Most functions can be set either by using one (or two) front-panel button(s) or knob(s), or by pushing a front-panel button to use a main menu, and then a side-menu button to set the function. The following steps illustrate both procedures. 1. Locate the block that contains the function to be set. Vertical function controls. Access all vertical functions and inputs from this front-panel control block. Horizontal function controls.
Operating Instructions 2. Select the waveform source(s). Position, scale, and set trigger level for waveform source(s) directly from the front panel. The steps that follow provide examples of possible control selections. 1 2 3 4 8 7 6 5 a. Input waveforms into these channels (7). Example: CH 1. b. Push any channel’s button (8) to display its waveform. The last channel turned on determines which waveform is positioned and scaled. The indicator above the channel last selected is lighted.
Operating Instructions e. Adjust trigger level (6) to trigger the waveform(s) selected or use these buttons (5) to either set a trigger level at the mid-amplitude level of the selected waveform or to force a single trigger. Example: Push SET LEVEL TO 50%. 3. Set all other functions using menus. a. Choose the waveform source (8) first if setting a vertical function; else skip to step b. Example: Push CH 2. b. Push SHIFT (4) if the function to be set is highlighted in blue; else skip to step c.
Operating Instructions e. Select the setting for the function from the side menu (9) using the side-menu buttons (11). Example: Push AC (10). How to Set Complex Functions A few functions require more than just two levels (main and side) of menus to completely specify their settings. In such cases, either the main menu, the side menu, or both are modified to supply additional choices. The procedures that follow show both schemes. 1. Set up a function using pop-up menus: 15 18 17 16 a.
Operating Instructions 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 pushed TRIGGER MENU.) 19 20 21 a. Pushing some main-menu buttons displays a side menu with labels containing readouts that can be varied. Example: Push Level (21). b. Pushing the side-menu button Level assigns the general purpose knob to control the readout appearing in the button label.
Operating Instructions H Gated measurements H Number of events H Template generation H Trigger position H Holdoff H Offset H Variable persistence In all cases, the menus are used to select the function to which the general purpose knob is assigned.
Operating Instructions 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 the Display menu, you can set the following functions: H Color: waveforms, readouts, graticule H Intensity: waveforms, readouts, graticule, etc.
Operating Instructions 2–16 TDS 684A, TDS 744A, & TDS 784A Service Manual
Theory of Operation This section describes the electrical operation of the TDS 684A and 7XXA Digitizing Oscilloscopes using the major circuit blocks or modules. This section has two main parts: H Logic Conventions describes how logic functions are discussed and represented in this manual. H Module Overview describes circuit operation from a functional-circuit block perspective. Logic Conventions The Digitizing Oscilloscopes contain many digital logic circuits.
Theory of Operation selected and the input is overloaded, the processor system switches the input to the 1 MW position. Probe Coding Interface. Probe coding interface signals pass through the attenuator portion of the A10 Attenuator/Acquisition to the acquisition system, where they are sensed and controlled. Acquisition System. The acquisition system amplifies the input signals, samples them, converts them to digital signals, and controls the acquisition process under direction of the processor system.
Theory of Operation Front Panel The processor system sends instructions to and receives information from the Front Panel Processor on the A12 Front Panel board. The Front Panel Processor reads the front-panel switches and potentiometers. Any changes in their settings are reported to the processor system. The Front Panel Processor also turns the LEDs on and off and generates the bell signal. Front-panel menu switches are also read by the Front Panel Processor.
Theory of Operation 3–4 TDS 684A, TDS 744A, & TDS 784A Service Manual
Performance Verification Procedures Two types of Performance Verification procedures can be performed on this product; Brief Procedures and Performance Tests. You may not need to perform all of these procedures, depending on what you want to accomplish. H To rapidly confirm that the oscilloscope functions and was adjusted properly, just do the brief procedures under Self Tests, which begin on page 4–5.
Performance Verification Procedures 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 consists of as many steps, substeps, and subparts as required to do the test. Steps, substeps, and subparts are sequenced as follows: 1. First Step a. First Substep H First Subpart H Second Subpart b. Second Substep 2.
Performance Verification Procedures the five buttons to the right of the display. “Pop-up menu” refers to a menu that pops up when a main-menu button is pressed. Position of waveform record relative to the screen and display General purpose knob readout Brief status information Side menu area. Readouts for measurements move here when CLEAR MENU is pressed.
Performance Verification Procedures 4–4 TDS 684A, TDS 744A, & TDS 784A Service Manual
Brief Procedures The Self Tests use internal routines to confirm basic functionality and proper adjustment. No test equipment is required to do these test procedures. The Functional Tests utilize the probe-compensation output at the front panel as a test-signal source for further verifying that the oscilloscope functions properly. A probe, such as the P6245, is required to do these test procedures.
Brief Procedures e. Confirm the three adjustment sections have passed status: f. H Press SHIFT; then press UTILITY. H Highlight Cal in the pop-up menu by repeatedly pressing the main-menu button System. See Figure 4–2. H Verify that the word Pass appears in the main menu under the following menu labels: Voltage Reference, Frequency Response, and Pulse Trigger. See Figure 4–2.
Brief Procedures 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 functions properly. The only equipment required is one of the standard-accessory probes and, to check the file system, a 3.5 inch, 720 K or 1.44 Mbyte floppy disk. CAUTION.
Brief Procedures Verify All Input Channels Equipment Required 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 COMPENSATION SIGNAL on the front panel; connect the probe ground (typically black) to PROBE COMPENSATION GND. If using a P6245 probe, you may want to attach a Y-lead connector and two SMD KlipChips as shown in Figure 4–3.
Brief Procedures 2. Verify that all channels operate: Do the following substeps — test CH 1 first, skipping substep a and b since CH 1 is already set up for verification and as the trigger source from step 1. a. Select an unverified channel: H Press WAVEFORM OFF to remove the channel just verified from display. H Press the front-panel button that corresponds to the channel you are to verify. H Move the probe to the channel you selected. b.
Brief Procedures f. 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 acquiring waveform on-screen with the noise present in Sample mode “peak detected.” H Hi Res mode (TDS 7XXA only) displays an actively acquiring waveform on-screen with the noise that was present in Sample mode reduced.
Brief Procedures a. One period of the square-wave probe-compensation signal is about five horizontal divisions on-screen for the 200 ms horizontal scale setting (set in step 1c). b. Rotating the horizontal SCALE knob clockwise expands the waveform on-screen (more horizontal divisions per waveform period), counterclockwise rotation contracts it, and returning the horizontal scale to 200 ms returns the period to about five divisions. c.
Brief Procedures 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 the trigger-LEVEL knob. H The trigger-LEVEL knob can trigger and untrigger the square-wave signal as you rotate it. (Leave the signal untriggered, which is indicated by the display not updating.) H Pressing SET LEVEL TO 50% triggers the signal that you just left untriggered. (Leave the signal triggered.) 3.
Brief Procedures H Verify that the trigger READY indicator on the front panel flashes about 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 terminals. Verify the File System Equipment Required One probe such as the P6245 or P6139A Prerequisites None One 720 K or 1.44 Mbyte, 3.5 inch DOS-compatible disk. You can use a disk of your own or you can use the Programming Examples Software 3.
Brief Procedures e. Save the settings: H Press SETUP. H Press the main-menu button Save Current Setup; then press the side-menu button To File. H Turn the general purpose knob to select the file to save. Choose (or ). With this choice, you will save a file starting with , then containing 5-numbers, and a extension.
Performance Tests This section contains a collection of procedures for checking that the TDS 684A and 7XXA Digitizing Oscilloscopes perform as warranted. The procedures are arranged in four logical groupings: Signal Acquisition System Checks, Time Base System Checks, Triggering System Checks, and Output Ports Checks. They check all the characteristics that are designated as checked in Specifications.
Performance Tests Equipment Required These procedures use external, traceable signal sources to directly check warranted characteristics. The required equipment list follows this introduction. Table 4–1: Test Equipment Item Number and Description Minimum Requirements Example Purpose 1. Attenuator,10X (two required) Ratio: 10X; impedance 50 ; connectors: female BNC input, male BNC output Tektronix part number 011-0059-02 Signal Attenuation 2.
Performance Tests Table 4–1: Test Equipment (Cont.) Item Number and Description Minimum Requirements 15. 3.5 inch, 720 K or 1.44 Mbyte, DOS-compatible floppy disk Example Purpose Programming Examples Software Disk (Tektronix part number 063-1134-XX) that comes with the TDS Family Programmer Manual (Tektronix part number 070-8709-XX) Checking File System Basic Functionality Used to Test Video Option 05 Equipped Instruments Only 16.
Performance Tests 4–18 TDS 684A, TDS 744A, & TDS 784A Service Manual
Performance Tests TDS 684A Test Record Photocopy this and the next three pages and use them to record the performance test results for your TDS 684A. TDS 684A Test Record Instrument Serial Number: Temperature: Date of Calibration: TDS 684A Performance Test Certificate Number: RH %: Technician: Minimum Incoming Outgoing Maximum Offset Accuracy CH1 Offset +1 mV +101 mV +1.01 V – 1.45 mV – 69.1 mV – 691 mV __________ __________ __________ __________ __________ __________ + 1.45 mV + 69.
Performance Tests TDS 684A Test Record (Cont.) Instrument Serial Number: Temperature: Date of Calibration: Certificate Number: RH %: Technician: TDS 684A Performance Test Minimum Incoming Outgoing Maximum CH2 200 mV Vert scale setting, +5 Div position setting, –10 V offset – 11.786 V __________ __________ – 11.420 V CH2 1 V Vert scale setting, –5 Div position setting, +10 V offset + 17.26 V __________ __________ + 18.
Performance Tests TDS 684A Test Record (Cont.) Instrument Serial Number: Temperature: Date of Calibration: TDS 684A Performance Test Certificate Number: RH %: Technician: Minimum Incoming Outgoing Maximum N/A __________ __________ 100 ps –2.0 Div __________ __________ +2.0 Div Pulse-Glitch or Pulse-Width, Hor. scale ≤ 1 ms Lower Limit Upper Limit 2.5 ns 2.5 ns __________ __________ __________ __________ 7.5 ns 7.5 ns Pulse-Glitch or Pulse-Width, Hor.
Performance Tests TDS 684A Test Record (Cont.) Instrument Serial Number: Temperature: Date of Calibration: Certificate Number: RH %: Technician: TDS 684A Performance Test Minimum Incoming Outgoing Maximum CH 3 SIGNAL OUTPUT, 1 M Pk-Pk ≥ 80 mV __________ __________ Pk-Pk ≤ 120 mV CH 3 SIGNAL OUTPUT, 50 Pk-Pk ≥ 40 mV __________ __________ Pk-Pk ≤ 60 mV Frequency (CH1 Freq.) 950 Hz __________ __________ 1.
Performance Tests TDS 7XXA Test Record Photocopy this and the next three pages and use them to record the performance test results for your TDS 7XXA. TDS 7XXA Test Record Instrument Serial Number: Temperature: Date of Calibration: TDS 7XXA Performance Test Certificate Number: RH %: Technician: Minimum Incoming Outgoing Maximum Offset Accuracy CH1 Offset +1 mV +101 mV +1.01 V – 1.6 mV – 25.1 mV – 251 mV __________ __________ __________ __________ __________ __________ + 1.6 mV + 25.
Performance Tests TDS 7XXA Test Record (Cont.) Instrument Serial Number: Temperature: Date of Calibration: Certificate Number: RH %: Technician: TDS 7XXA Performance Test Minimum Incoming Outgoing Maximum CH2 200 mV Vert scale setting, +5 Div position setting, –10 V offset – 11.6615 V __________ __________ – 11.5385 V CH2 1 V Vert scale setting, –5 Div position setting, +10 V offset + 17.7785 V __________ __________ + 18.
Performance Tests TDS 7XXA Test Record (Cont.) Instrument Serial Number: Temperature: Date of Calibration: TDS 7XXA Performance Test Certificate Number: RH %: Technician: Minimum Incoming Outgoing Maximum N/A __________ __________ 50 ps –2.5 Div __________ __________ +2.5 Div Pulse-Glitch or Pulse-Width, Hor. scale ≤ 1 ms Lower Limit Upper Limit 3.5 ns 2.5 ns __________ __________ __________ __________ 6.5 ns 6.5 ns Pulse-Glitch or Pulse-Width, Hor.
Performance Tests TDS 7XXA Test Record (Cont.) Instrument Serial Number: Temperature: Date of Calibration: Certificate Number: RH %: Technician: TDS 7XXA Performance Test Minimum Incoming Outgoing Maximum CH 3 SIGNAL OUTPUT, 1 M Pk-Pk ≥ 88 mV __________ __________ Pk-Pk ≤ 132 mV CH 3 SIGNAL OUTPUT, 50 Pk-Pk ≥ 44 mV __________ __________ Pk-Pk ≤ 66 mV Frequency (CH1 Freq.) 950 Hz __________ __________ 1.
Performance Tests Signal Acquisition System Checks These procedures check those characteristics that relate to the signal-acquisition system and are listed as checked under Warranted Characteristics in Specifications. Check Offset Accuracy (Zero Setting) Equipment Required None Prerequisites The oscilloscope must meet the prerequisites listed on page 4–15 1. Preset the instrument controls: a. Initialize the oscilloscope: H Press save/recall SETUP. H Press the main-menu button Recall Factory Setup.
Performance Tests 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 setting listed.) H Press VERTICAL MENU. Press the main-menu button Fine Scale. H Use the keypad to enter the vertical scale. For the 1 mV setting, press 1, SHIFT, m, then ENTER. For the 101 mV setting, press 101, SHIFT, m, then ENTER. For the 1.01 V setting, press 1.01, then ENTER. H Press CLEAR MENU.
Performance Tests Read the measurement results. 2 Align the active cursor over the waveform. 1 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 the hookup: No hookup was required. Check DC Voltage Measurement Accuracy WARNING. The generator is capable of outputting dangerous voltages.
Performance Tests 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 a dual-banana connector followed by a 50 W precision coaxial cable to one side of a BNC T connector. See Figure 4–5.
Performance Tests a. Select an unchecked channel: H Press WAVEFORM OFF to remove the channel just confirmed from the display. H Press the front-panel button that corresponds to the channel you are to confirm. H Set the generator output to 0 V. H Move the test hookup to the channel you selected. b. Turn on the measurement Mean for the channel: H Press MEASURE, then press the main-menu button Select Measrmnt for CHx.
Performance Tests H Use the keypad to set vertical offset to the positive-polarity setting listed in the table for the current vertical scale setting. The baseline level will remain off screen. H Set the generator to the level and polarity indicated in the table for the vertical scale, position, and offset settings you have made. The DC test level should appear on screen. (If it doesn’t return, the DC accuracy check is failed for the current vertical scale setting of the current channel.) e.
Performance Tests H Repeat substeps c through f until all vertical scale settings, listed in Table 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. Set the generator output to 0 V. b. Disconnect the cable from the generator output at the input connector of the channel last tested.
Performance Tests 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, skipping substeps a and b since CH 1 is already set up for testing from step 1. a. Select an unchecked channel: H Press WAVEFORM OFF to remove the channel just confirmed from display.
Performance Tests Table 4–4: Analog Bandwidth Vertical Scale Attenuators (10X) Reference Amplitude (at 6 MHz) Horizontal Scale TDS 684A and 784A Test Frequency 100 mV none 600 mV (6 divisions) 1 ns 1 GHz 500 MHz ≥424 mV 1V none 5 V (5 divisions) 1 ns 1 GHz 500 MHz ≥3.535 V 500 mV none 3 V (6 divisions) 1 ns 1 GHz 500 MHz ≥2.121 V 200 mV none 1.
Performance Tests f. Read results. 3 Set the generator (reference) frequency to the test frequency from Table 4–4. 1 Set the horizontal scale from Table 4–4. 2 Measure the test signal: H Set the frequency of the generator, as shown on screen, to the test frequency in Table 4–4 that corresponds to the vertical scale set in substep d. See Figure 4–8. H Set the horizontal SCALE to the horizontal scale setting in Table 4–4 that corresponds to the vertical scale set in substep d.
Performance Tests STOP. Checking each channel’s bandwidth at all vertical scale settings is time consuming and unnecessary. You may skip checking the remaining vertical scale settings in Table 4–4 (that is, skip the following substep, h) if this digitizing oscilloscope has performed as follows: H Passed the 100 mV vertical scale setting just checked in this procedure. H Passed the Verify Internal Adjustment, Self Compensation, and Diagnostics procedure found under Self Tests, on page 4–5. NOTE.
Performance Tests 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 save/recall SETUP. H Press the main-menu button Recall Factory Setup. H Press the side-menu button OK Confirm Factory Init. b. Modify the initialized front-panel control settings: H Do not adjust the vertical position of any channel during this procedure.
Performance Tests 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 the generator amplitude, push SET LEVEL TO 50% frequently to speed up the updating of the waveform amplitude on screen. b. The horizontal SCALE should already be set to 500 ps. On the TDS 784A, now set it to 200 ps.
Performance Tests Read results. 4 Display the waveforms. 1 H Press the main-menu button Function; then press the side-menu button V Bars. H Press CLEAR MENU. H Align one V bar cursor to the time reference point of the left-most waveform edge and the other cursor to the time reference point of the right-most waveform edge by rotating the General Purpose knob. (Press SELECT to switch between the two cursors.) See Figure 4–10 on page 4–40.
Performance Tests ment column of Table 4–5. Note that these numbers may be either positive 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, and CH1 to CH4. Write down these numbers in the second measurement column of Table 4–5. Note that these numbers may be either positive or negative. l.
Performance Tests Time Base System Checks These procedures check those characteristics that relate to the Main and Delayed time base system and are listed as checked under Warranted Characteristics in Specifications.
Performance Tests 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 accuracies: a. Display the test signal: H Align the trigger T to the center vertical graticule line by adjusting the horizontal POSITION. See Figure 4–12 on page 4–44. H Press HORIZONTAL MENU. H Set horizontal modes.
Performance Tests Align the trigger T to the center graticule line. 1 Set 2 horizontal mode. 4 3 Check long–term sample rates and delay time accuracies against limits. Set horizontal scale and delayed time. Figure 4–12: Measurement of Accuracy — Long-Term and Delay Time 3. Disconnect the hookup: Disconnect the cable from the generator output at the input connector of CH 1.
Performance Tests 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. Modify the default setup: H Press VERTICAL MENU. H Press the main-menu button Coupling; then press the side-menu button to select 50 coupling. H Set the horizontal SCALE to 10 ns on the TDS 684A and 12.5 ns on the TDS 7XXA. c.
Performance Tests b. Set the trigger mode: Press TRIGGER MENU. Now press the main-menu button Mode & Holdoff; then press the side-menu button Normal. c. Set upper and lower limits that ensure triggering: See Figure 4–14. H Press the main-menu button Type; then repeatedly press the same button until Pulse is highlighted in the menu that pops up. H Press the main-menu button Class; then repeatedly press the same button until Width is highlighted in the menu that pops up.
Performance Tests Set upper and lower limits that ensure triggering. Then change limits until triggering stops. Figure 4–14: Measurement of Time Accuracy for Pulse and Glitch Triggering 3. Confirm the trigger system is within time-accuracy limits for pulse-glitch or pulse-width triggering (horizontal scale >1 s): a. Set upper and lower limits that ensure triggering at 250 kHz: H Press the side-menu button Upper Limit. Use the keyboard to set the upper limit to 4 ms.
Performance Tests H CHECK that the Lower Limit readout, after the oscilloscope stops triggering, is within 1 ms to 3 ms, inclusive, for the TDS 684A or is within 1.9 ms to 2.1 ms, inclusive, for the TDS 7XXA. H Enter time on test record. H Use the keypad to return the Lower Limit to 500 ns and reestablish triggering. H Press the side-menu button Upper Limit; then use the general purpose knob to slowly decrease the Upper Limit readout until triggering stops.
Performance Tests H Connect the output of the DC calibration generator, through a dual-banana connector followed by a 50 W precision coaxial cable, to one side of a BNC T connector. H Connect the Sense output of the generator, through a second dual-banana connector followed by a 50 W precision coaxial cable, to other side of the BNC T connector. Now connect the BNC T connector to CH 1. b. Initialize the oscilloscope: H Press save/recall Setup. H Press the main-menu button Recall Factory Setup.
Performance Tests c. Read results (Check against limits): See Figure 4–16. Set vertical position to –3 divs. Set vertical offset to +10 volts. H CHECK that the Level readout in the main menu is within 9.863 V to 10.137 V, inclusive, for the TDS 684A or is within 9.9393 V to 10.1147 V, inclusive, for the TDS 7XXA. H Enter voltage on test record. H Press the main-menu button Slope; then press the side-menu button for negative slope. See icon at left. Repeat substep b.
Performance Tests H Press HORIZONTAL MENU. H Press the main-menu button Time Base. H Press the side-menu buttons Delayed Only and Delayed Triggerable. H Set D (delayed) horizontal SCALE to 500 ms. b. Select the Delayed trigger system: H Press SHIFT; then press the front-panel DELAYED TRIG button. H Press the main-menu button Level. c. Measure the test signal: Press the side-menu button SET TO 50%. Read the measurement results in the side (or main) menu below the label Level. d.
Performance Tests Sensitivity, Edge Trigger, DC Coupled Equipment Required 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 (Item 7) One 5X attenuator (Item 2) Prerequisites See page 4–15. 1. Install the test hookup and preset the instrument controls: a. Initialize the oscilloscope: H Press save/recall SETUP.
Performance Tests 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 To AUX TRIG INPUT on Rear Panel Digitizing Oscilloscope Figure 4–17: Initial Test Hookup 2. Confirm Main and Delayed trigger systems are within sensitivity limits (50 MHz): a. Display the test signal: H Set the generator frequency to 50 MHz. H Press MEASURE. H Press the main-menu button High-Low Setup; then press the side-menu button Min-Max.
Performance Tests triggered on the selected slope (positive or negative). This display should not have its trigger point switching between opposite slopes, nor should it roll across the screen. At horizontal scale settings of 2 ms/division and faster, TRIG’D will remain constantly lighted. It will flash for slower settings. H Press TRIGGER MENU; then press the main-menu button Slope. H Press SET LEVEL TO 50%. Adjust the TRIGGER LEVEL knob so that the TRIG’D light is on.
Performance Tests c. Check Delayed trigger system for stable triggering at limits: Do the following subparts in the order listed. H Press HORIZONTAL MENU; then press the main-menu button Time Base. Press the side-menu button Delayed Only; then press Delayed Triggerable in the same menu. H Press SHIFT; then press DELAYED TRIG. Press the main-menu button Level. H Press the side-menu button SET TO 50%.
Performance Tests H Press SET LEVEL TO 50%. CHECK that a stable trigger is obtained for the test waveform on both the positive and negative slopes. Press the main-menu button Slope; then use the side menu to switch between trigger slopes. Use the TRIGGER LEVEL knob to stabilize the trigger if required. H Enter the pass/fail result on the test record. H Leave the Main trigger system triggered on the positive slope of the waveform before proceeding to the next check.
Performance Tests 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 Signal Checks The procedure that follows checks those characteristics of the output signals that are listed as checked under Warranted Characteristics in Specifications. The oscilloscope outputs these signals at its front and rear panels.
Performance Tests 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 ms. H Press SHIFT; then press ACQUIRE MENU. H Press the main-menu button Mode; then press the side-menu button Average. H Select 64 averages. 2. Confirm Main and Delayed Trigger outputs are within limits for logic levels: a.
Performance Tests 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 Delayed Trigger Output BNC. H CHECK that the Ch2 High readout is ≥1.0 volt and that the Ch2 Low readout ≤0.25 volts. H Enter high and low voltages on test record. H Press the side-menu button to select the 1 MW setting. H Press CLEAR MENU.
Performance Tests 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 Select Measrmnt for Ch2. H Repeatedly press the side-menu button –more– until Pk-Pk appears in the side menu (its icon is shown at the left). Press the side-menu button Pk-Pk. H Press CLEAR MENU. b.
Performance Tests 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 female BNC-to-clips adapter. See Figure 4–21. H Connect the red clip on the adapter just installed to the PROBE COMPENSATION SIGNAL on the front panel; connect the black clip to PROBE COMPENSATION GND. See Figure 4–21.
Performance Tests 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 Select Measrmnt for Ch1. H Repeatedly press the side-menu button –more– until Frequency appears in the side menu (its icon is shown at the left). Press the side-menu button Frequency. b. Check against limits: H CHECK that the CH 1 Freq readout is within 950 Hz to 1.
Performance Tests H Press SAVE/RECALL WAVEFORM; then press the main-menu button Save Wfm Ch 1. H Press the side-menu button To Ref 1 to save the probe compensation signal in reference 1. H Disconnect the cable from CH 1 and the clips from the probe compensation terminals. H Press MORE; then press the main-menu button Ref 1 to displayed the stored signal. H Press CH 1. d. Hook up the DC standard source: H Set the output of a DC calibration generator to 0 volts.
Performance Tests f. H Adjust the output of the DC calibration generator until it precisely overlaps the top (upper) level of the stored probe compensation signal. (This value will be near 500 mV.) H Record the setting of the DC generator. H Adjust the output of the DC calibration generator until it precisely overlaps the base (lower) level of the stored probe compensation signal. (This value will be near zero volts.) H Record the setting of the DC generator.
Performance Tests Option 05 Video Trigger Checks Check Video Trigger Equipment Required 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 cable (Item 5) 50 terminator (Item 4) Prerequisites See page 4–15. These prerequisites include running the signal path compensation routine. 1. Set up digitizing oscilloscope to factory defaults by completing the following steps: a.
Performance Tests 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 the main-menu Horiz Scale. m. Use the keypad to set the horizontal scale to 200 ns (press 200, SHIFT, n, then ENTER). 3. Check Jitter vs. Signal Amplitude a. Set up equipment for Jitter Test. See Figure 4–25.
Performance Tests 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 Limit Test Template. g. Press the side-menu V Limit. h. Use the keypad to set V Limit to 180 mdiv (press 180, SHIFT, m, then ENTER) i. Press the side-menu OK Store Template. j. Press MORE. k. Press the main-menu Ref1. l. Press CH1. m.
Performance Tests 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, then ENTER). t. Press the main-menu Stop After button. u. Press the side-menu Single Acquisition Sequence. v. Confirm that the oscilloscope successfully makes 100 acquisitions. If not successful, the oscilloscope bell will ring. When the word Run in the top left corner of the display changes to STOP, the test is complete. See Figure 4–27.
Performance Tests b. Press WAVEFORM OFF. c. Press HORIZONTAL MENU. d. Use the keypad to set horizontal scale (/div) to 50 ms (press 50, SHIFT, m, then ENTER). e. Press SHIFT; then press ACQUIRE MENU. f. Press the main-menu Stop After. g. Press the side-menu RUN/STOP button only. h. Press the main-menu Mode. i. Press the side-menu Sample. j. Press RUN/STOP. k. Press VERTICAL MENU. l. Use the keypad to set fine scale to 300 mV (press 300, SHIFT, m, then ENTER). m.
Performance Tests 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 waveform on screen is stable. That is, it does not move horizontally or vertically. Also, CONFIRM that the waveform on the screen has one positive pulse and a number of negative pulses. See Figure 4–29.
Performance Tests Positive pulse Negative pulses Figure 4–29: Triggered Signal Range Test – 75 mV p. Disconnect all test equipment (TSG121) from the digitizing oscilloscope. 5. Check 60 Hz Rejection. a. Set up oscilloscope for 60 Hz Rejection Test. H Use the keypad to set the Ch1 Fine Scale to 282 mV (press 282, SHIFT m, then ENTER). H Press WAVEFORM OFF. H Press CH2. H Press VERTICAL MENU. H Use the keypad set the fine scale to 2 V (press 2, then ENTER). H Press HORIZONTAL MENU.
Performance Tests Digitizing Oscilloscope Signal Generator Output 50 Cable Figure 4–30: 60 Hz Rejection Test Hookup H Adjust the SG 502 for three vertical divisions of 60 Hz signal. See Figure 4–31. The signal will not be triggered. That is, it will run free. Figure 4–31: 60 Hz Rejection Test Setup Signal c. Check 60 Hz rejection. 4–72 H Use the keypad to set the horizontal scale (/div) to 50 ms (press 50, SHIFT, m, then ENTER). H Reconnect the output of the signal generator (SG 502).
Performance Tests 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. See Figure 4–32. H Press VERTICAL MENU. H If needed, press the main-menu Fine Scale. H Use the keypad to set fine scale to 500 mV (press 500, SHIFT, m, then ENTER). H Connect another composite signal connector of the PAL signal source (labeled COMPST on the TSG 121) through a 75 W cable and a 75 W terminator to the CH2 input. See Figure 4–32.
Performance Tests 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 Record Length. H Press the side-menu –more– until you see the appropriate menu. H Press the side-menu 5000 points in 100divs. H Press the main-menu Horiz Scale (/div).
Performance Tests PAL Signal Source Digitizing Oscilloscope Output 75 Cable 75 Terminator 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 Pos. H Press the side-menu to Set to 50%. H Use the HORIZONTAL POSITION knob to move the falling edge of the sync pulse to two divisions to the left of center screen. See Figure 4–35.
Performance Tests Figure 4–35: Line Count Accuracy Test Setup Waveform – TDS 684A Shown 4–76 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 over the trigger ‘T’ icon. H Press SELECT. H Turn the General Purpose knob to adjust the right cursor for a cursor delta reading of 6.780us. H Use the HORIZONTAL POSITION knob to position the right cursor to center screen.
Performance Tests Figure 4–36: Line Count Accuracy Correct Result Waveform H Disconnect all test equipment (TSG 121) from the digitizing oscilloscope. H Turn off cursors by pressing CURSOR, then the main-menu Function button, and, finally, Off from the side menu. 7. Check the Sync Duty Cycle. a. Set up digitizing oscilloscope for Sync Duty Cycle Test. H Press TRIGGER MENU. H Press the Standard pop-up to select FlexFmt. Trigger Type should already be set to Video. H Press the main-menu Setup.
Performance Tests H Press the side-menu Fields. H Use the keypad to set the number of fields to 1 (press 1, then ENTER). H Press the side-menu Sync Width. H Use the keypad to set the width to 400 ns (press 400, SHIFT, n, then ENTER). H Press the side-menu –more– 1 of 2. Then press V1 Start Time. H Use the keypad to set V1 start time to 10.10 ms (press 10.10, SHIFT, m, then ENTER). H Press the side-menu V1 Stop Time. H Use the keypad to set V1 stop time to 10.50 ms (press 10.
Performance Tests 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 Output 50 Cable 50 Terminator Figure 4–37: PG502 Setup for Sync Duty Cycle Test H Turn the pulse generator OUTPUT (VOLTS) control until the signal on the oscilloscope shows a one division negative going pulse. See Figure 4–38. NOTE.
Performance Tests Figure 4–38: Sync Duty Cycle Test: One-Div Neg Pulse Waveform H Turn the pulse generator PULSE DURATION variable control to adjust the negative pulse so the oscilloscope’s CH1 – Width measurement displays 400ns +/–10 ns. H Turn the HORIZONTAL SCALE knob to set the oscilloscope time base to 5ms/div. H Turn the pulse generator PERIOD variable control to adjust the period until the oscilloscope CH1 Period measurement reads 21.000ms –25/+50 ns. See Figure 4–39. Read note shown below.
Performance Tests 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 and CH1 Period measurements are adjusted correctly. See note above. CONFIRM that the setup is correct and the oscilloscope will trigger. H CONFIRM that the TRIG’D LED is lighted and the waveform is stable.
Performance Tests 4–82 H Disconnect the signal source from CH1, wait a few seconds, then reconnect the signal. H CONFIRM that the TRIG’D LED is lighted and the waveform is stable. H Disconnect all test equipment (TSG 121) from the digitizing oscilloscope. H Press save/recall SETUP, the main-menu button Recall Factory Setup, and the side-menu OK Confirm Factory Init.
Adjustment Procedures This section contains information needed to adjust the TDS 684A and 7XXA Digitizing Oscilloscopes. Description Purpose Adjustment Interval The Adjustment Procedures are divided into six subsections: H General information about adjusting the TDS 684A and 7XXA Digitizing Oscilloscopes. H A list of equipment required to perform the adjustments. H The written procedures for installing and using both the TDS 684A Adjustment Software and the TDS 700A Adjustment Software.
Adjustment Procedures Two small holes in the chassis allow service personnel to insert a tool and push a switch to enable or disable the writing of new adjustment constants to nonvolatile RAM. The procedure that follows will tell you how and when to enable and disable the writing of adjustment constants. Be sure to disable the switch when you have finished adjusting the oscilloscope. System The following computer and peripherals are required to adjust this oscilloscope.
Adjustment Procedures Since the display-assembly and P6139A probe adjustment require manual adjustment 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 the optional P6139A probe, do the manual adjustment procedures found at the end of this section.
Adjustment Procedures Adjustment After Repair After the removal and replacement of a module due to electrical failure, you must either do a complete adjustment or no adjustment at all, depending on the module replaced. See Table 5–2.
Adjustment Procedures Equipment Required Table 5–4 lists the test equipment required to adjust the TDS 684A and 7XXA Digitizing Oscilloscopes. Table 5–4: Test Equipment, Fixtures, and Supplies Item Number and Description Minimum Requirements Example Purpose 1. Adapter, BNC-Female-toBNC-Female Tektronix part number 013-0028-00 Tektronix part number 013-0028-00 Probe Adjustment 2.
Adjustment Procedures Table 5–4: Test Equipment, Fixtures, and Supplies (Cont.) Item Number and Description Minimum Requirements Example Purpose 14. Generator, Leveled Sine Wave, High-Frequency 250 MHz to 1 GHz; Variable amplitude from 0.
Adjustment Procedures Adjustment Instructions The following instructions describe installing the software on your system, setting up the oscilloscope for adjustment, and starting the adjustment of the oscilloscope by the software. Hardware Installation 1. Install the proper GPIB card (see System on page 5–2): Use the manual accompanying your GPIB card to install and configure that card. 2. Configure the GPIB card: a. This software is compatible with cards configured for PCII and PCIIA operation.
Adjustment Procedures 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 adjustment software. It will also prompt you to specify several GPIB-card configuration parameters. b. The adjustment software will be installed in a directory called TDS684.ADJ or TDS700.ADJ on your hard drive. 3. Store your installation disk: Remove your installation disk and store in a secure place.
Adjustment Procedures 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 above: a. Locate the two small access holes on the right side of the oscilloscope cabinet near the front. b. Insert the adjustment tool (Item 3) in the hole nearest the front of the oscilloscope about 1/2 inch to engage the rocker switch. c.
Adjustment Procedures 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 front. (See Figure 5–1.) b. Insert the adjustment tool (Item 3) in the hole nearest the rear of the oscilloscope about 1/2 inch to engage the rocker switch. c. Push to rock the switch to its protected (disabled) position. d.
Adjustment Procedures 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 the front panel; connect the probe ground to PROBE COMPENSATION GND. b. Initialize the oscilloscope: H Press save/recall SETUP. H Press the main-menu button Recall Factory Setup. H Press the side-menu button OK Confirm Factory Init. c. Modify the initialized front-panel control settings: H Press AUTOSET.
Adjustment Procedures 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 compensation (flat as possible across its top).
Adjustment Procedures 3. Disconnect the hookup: Disconnect the probe from the probe compensator terminals; leave probe installed on CH 1 and leave the oscilloscope control setup as is for doing the next part of probe adjustment. Measure Probe Bandwidth Equipment Required One high-frequency sine wave generator with its leveling head (Item 14) One BNC-female-to-female BNC adapter (Item 1) One BNC-to-probe tip adapter (Item 2) One P6139A 10X probe (Item 17) 1.
Adjustment Procedures High Frequency Sine Wave Generator Digitizing Oscilloscope Output BNC-Female-toLeveling Head Female BNC Adapter BNC-to Probe Tip Adapter Figure 5–6: Initial Test Hookup c. Initialize the oscilloscope: 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 vertical SCALE to 500 mV. H Set the horizontal SCALE to 100 ns.
Adjustment Procedures a. Display and measure the test signal: H Monitor the CH 1 Pk-Pk readout while you set the output of the generator for a 3.0 V (6 division), 6 MHz reference signal. H Set the horizontal SCALE to 1 ns and set the frequency of the generator to 500 MHz. H Read the measurement results at the CH 1 Pk-Pk readout on screen. b. Check against limits: CHECK that the CH 1 Pk-Pk readout is greater than or equal to 2.1 V. 3. Disconnect the hookup: a.
Adjustment Procedures a. Access Inner Probe Tip and Adjustment Ports: H The probe tip should be exposed from the procedure Measure Probe Bandwidth. If not, follow the instructions in Figure 5–5 to expose the probe tip. H Follow the instructions in Figure 5–7 to remove the probe body covers. Use a small standard screwdriver to pry between the cover and metal cord connector to pop off cover. Repeat for lower cover. Figure 5–7: Exposing the Probe Body b.
Adjustment Procedures Calibration Generator Digitizing Oscilloscope Output 10X Attenuator Tunnel Diode Pulser Precision Cable Figure 5–8: Initial Test Hookup c. Initialize the oscilloscope: 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 vertical SCALE to 5 mV. H Push SET LEVEL TO 50% as required to trigger the signal. H Press VERTICAL MENU.
Adjustment Procedures H Press SHIFT; then press ACQUIRE MENU. H Press the main-menu button Mode. Then press the side-menu button Average 16. H Push SET LEVEL TO 50% as required to trigger the signal. H Advance the horizontal SCALE to 5 ns. H Press HORIZONTAL MENU. H Press the main-menu button Trigger Position; press the side-menu button Set to 20%. H Press SAVE WAVEFORM. H Press the main-menu button Save Waveform. Then press the side-menu button To Ref 1. H Press MORE.
Adjustment Procedures R1 Not Used R2 C1 LF Comp Figure 5–9: Locations of P6139A Probe Adjustments H See Figure 5–10 to see what areas on the front corner that the various adjustments affect. d. Recheck Probe Bandwidth: H Redo the procedure Adjust Probe — High Frequency Response to check if probe now meets its bandwidth requirement. H If the bandwidth requirement is met, adjustment is complete. Skip to step 3.
Adjustment Procedures 20 ns R1 10 ns R2 5 ns C1 1 Adjust R1 for best overall match. Adjust R2 and C1 for best match 2 between front corners. Repeat the first two steps as needed 3 due to interaction between adjustments. Figure 5–10: Adjustments versus Front-Corner Response 3. Disconnect the hookup: Unplug the probe from the BNC-to-probe tip adapter. Reverse the instructions in Figure 5–5, page 5–13, to reinstall the retractable probe tip.
Adjustment Procedures 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 or if brightness and contrast have become unsatisfactory. Rotation, Brightness, and Contrast Adjustment Equipment Required One 6X magnifier (Item 15) One J16 Photometer with a J6503 Luminance Probe (Item 16) 1.
Adjustment Procedures 3. Adjust the display brightness H Locate R403 (BRIGHTNESS). It is one of the adjustments on the left side of the instrument located just ahead of the fan. It is the fourth adjustment from the fan. H Observe the luminance patches using a 6X magnifier. H Adjust R403 (BRIGHTNESS) until the background raster lines in the 5% luminance patch (see Figure 5–11) just disappear, while the lines in the 10% luminance patch are just visible, when both are viewed through the magnifier.
Adjustment Procedures H Press the main-menu button EXECUTE; then press the side-menu button Ok Confirm Run Test. b. Make the contrast adjustment: H Locate R404. It is one of the adjustments on the left side of the instrument located just ahead of the fan. It is the fifth adjustment from the fan. H Monitor the luminance at center screen using a J16 photometer and a luminance probe. H Adjust R404 (CONTRAST) for a reading of 40 foot lamberts. NOTE.
Adjustment Procedures 5–24 TDS 684A, TDS 744A, & TDS 784A Service Manual
Maintenance This section contains the information needed to do periodic and corrective maintenance on the TDS 684A and 7XXA Digitizing Oscilloscopes. The following subsections are included: H Preparation — Introduction plus general information on preventing damage to internal modules when doing maintenance. H Inspection and Cleaning — Information and procedures for inspecting the oscilloscope and cleaning its external and internal modules.
Maintenance H Section 10, Mechanical Parts List, lists all field replaceable modules by part number. Preparation Preventing ESD CAUTION. Static discharge can damage any semiconductor component in this oscilloscope. Precautions. When performing any service which requires internal access to the oscilloscope, adhere to the following precautions to avoid damaging internal modules and their components due to electrostatic discharge (ESD). 1. Minimize handling of static-sensitive modules. 2.
Maintenance Table 6–1: Relative Susceptibility to Static-Discharge Damage Semiconductor Classes Relative Susceptibility Levels1 MOS or CMOS microcircuits or discrete circuits, or linear microcircuits with MOS inputs (most sensitive) 1 ECL 2 Schottky signal diodes 3 Schottky TTL 4 High-frequency bipolar transistors 5 JFET 6 Linear microcircuits 7 Low-power Schottky TTL 8 TTL (least sensitive) 9 1 Voltage equivalent for levels (voltage discharged from a 100 pF capacitor through resistanc
Maintenance Inspection and Cleaning Inspection and Cleaning describes how to inspect for dirt and damage on, and how to clean the exterior and interior of the TDS 684A and 7XXA Digitizing Oscilloscopes. Inspection and cleaning are done as preventive maintenance. Preventive maintenance, when done regularly, may prevent oscilloscope malfunction and enhance its reliability. Preventive maintenance consists of visually inspecting and cleaning the oscilloscope and using general care when operating it.
Maintenance 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 defective module. Front-panel knobs Missing, damaged, or loose knobs. Repair or replace missing or defective knobs. Connectors Broken shells, cracked insulation, Repair or replace defective and deformed contacts. Dirt in modules. Clear or wash out dirt. connectors. Carrying handle, bail, cabinet feet.
Maintenance 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 Loose, broken, or corroded solder connections. Burned circuit boards. Burned, broken, or cracked circuit-run plating. Remove failed module and replace with a fresh module. Resistors Burned, cracked, broken, blistered condition.
Maintenance STOP. If, after doing steps 1 and 2, a module is clean upon inspection, skip the remaining steps. 3. If steps 1 and 2 do not remove all the dust or dirt, the oscilloscope may be spray washed using a solution of 75% isopropyl alcohol by doing steps 4 through 8. 4. Gain access to the parts to be cleaned by removing easily accessible shields and panels (see Removal and Installation Procedures). 5.
Maintenance 6–8 TDS 684A, TDS 744A, & TDS 784A Service Manual
Removal and Installation Procedures This subsection contains procedures for removal and installation of all mechanical and electrical modules. Any electrical or mechanical module, assembly, or part listed in Section 10 of this manual is a module. Preparation — Please Read WARNING. Before doing this or any other procedure in this manual, read the Safety Summary found at the beginning of this manual.
Removal and Installation Procedures General Instructions STOP. READ THESE GENERAL INSTRUCTIONS BEFORE REMOVING A MODULE. First read over the Summary of Procedures that follows to understand how the procedures are grouped. Then read Equipment Required for a list of the tools needed to remove and install modules in this oscilloscope. If you are disassembling this oscilloscope for cleaning, go to the procedure Disassembly for Cleaning on page 6–53.
Removal and Installation Procedures tool whenever a procedure step instructs you to remove or install a screw unless a different size screwdriver is specified in that step. All equipment required to remove and reinstall each module is listed in the first step of its procedure. Table 6–4: Tools Required for Module Removal Item No.
Removal and Installation Procedures Rear Cover Cabinet Fuse Cap Line Fuse Line Cord EMI Gasket Handle Handle Cap Foot Foot Pad EMI Gasket Display Frame Flip Stand Front Panel Knobs Menu Buttons Attenuator Cover A12 Front Panel Assembly Trim Ring Front Cover Figure 6–1: External Modules 6–12 TDS 684A, TDS 744A, & TDS 784A Service Manual
Removal and Installation Procedures A11 DRAM Processor/Display Board Rear Chassis Fan Top Cover A23 SerPar Board Board Bracket A14 D1 Bus Analog and Digital Power Cables A10 Acquisition Board Figure 6–2: Outer-Chassis Modules TDS 684A, TDS 744A, & TDS 784A Service Manual 6–13
Removal and Installation Procedures A30 Display Assembly A16 Power Supply Main Chassis Front Subpanel Figure 6–3: Inner-Chassis Modules 6–14 TDS 684A, TDS 744A, & TDS 784A Service Manual
Removal and Installation Procedures Access Procedure Begin with this procedure when you have identified a module to be removed for service and have read General Instructions found earlier in this section. 1. Locate module to be removed: a. Find the module to be removed in the module locator diagrams, Figures 6–1 through 6–3. b. Once the module is found, note from the title of the figure whether the module is an external, outer-chassis mounted, or inner-chassis mounted part. 2.
Removal and Installation Procedures c. Do, in the order listed, the three procedures A14 D1 Bus and AnalogPower and Digital-Power Cables, A11 Processor/Display Board and Top Cover found under Procedures for Outer-Chassis Modules, page 6–29. d. Find and do the procedure whose title matches the name of the module to be removed under Procedures for Inner-Chassis Modules, page 6–46. 6.
Removal and Installation Procedures 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 Line Fuse and Line Cord 1. Assemble equipment and locate modules to be removed: Have a flat-bladed screwdriver (Item 5) handy. Locate the line fuse and line cord in the locator diagram External Modules, Figure 6–1. 2.
Removal and Installation Procedures 5. Reinstallation: Do in reverse steps 3 and 4 to reinstall the line cord and then the line fuse. 1 Unplug 2 Rotate Line Fuse Fuse Cap 3 Pull Figure 6–5: Line Fuse and Line Cord Removal EMI Gaskets Rear Cover and Cabinet See Rear Cover and Cabinet procedure on page 6–18. 1. Assemble equipment and locate modules to be removed: a. Have handy a screwdriver with a size T-20 TorxR tip (Items 1 and 3). b.
Removal and Installation Procedures 3. Disconnect the line cord: Unplug the line cord from its receptacle at the rear cover. 4. Remove rear cover: Remove the four screws securing the rear cover to the oscilloscope. Lift off the rear cover. 5. Remove the cabinet: a. At the rear of the cabinet, grasp its left and right edges. b. Pull upward to slide the cabinet off the oscilloscope. Take care not to bind or snag the cabinet on the oscilloscope’s internal cabling as you remove it. STOP.
Removal and Installation Procedures b. Take care not to bind or snag the cabinet on internal cabling; redress cables an necessary. c. When sliding the cabinet, be sure that the front edge of the cabinet aligns with the groove containing the EMI shield on the front casting. d. Be sure that the ridge around the rear chassis slides into the groove containing a second EMI cable on the rear of the cabinet. e. When reinstalling the four screws at the rear panel, tighten them to 16 foot-lbs torque. f.
Removal and Installation Procedures Figure 6–6: Rear Cover and Cabinet Removal TDS 684A, TDS 744A, & TDS 784A Service Manual 6–21
Removal and Installation Procedures Front Cover, Trim Ring, Menu Buttons, and Attenuator Panel 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 oscilloscope so its rear is down on the work surface and its bottom is facing you. 3. Remove the front cover: Grasp the front cover by its left and right edges and snap it off of the front subpanel.
Removal and Installation Procedures 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 menu buttons, lift them out of the trim ring. (When reinstalling, reinsert the menu buttons, align the trim ring to the front subpanel and press it back on.) 5. Remove the attenuator panel: Gently pry, using your fingers, the snap-off/ snap-on attenuator panel away from the front subpanel to remove it.
Removal and Installation Procedures P3 P2 Torxdrive Screw T–15 Quick Disconnect Stud Mount W76 Cable Power Assembly Ground P2 Front-Panel Assembly Back of Front–Panel Assembly Ground Figure 6–8: A12 Front-Panel Assembly Removal 4. Further disassembly of front-panel assembly: If the front panel or the front-panel buttons are to be serviced, do the following substeps: a. Remove the front-panel control knobs from the front-panel assembly using the method described in Front-Panel Knobs on page 6–16. b.
Removal and Installation Procedures c. Now hand disassemble the front-panel assembly components using Figure 6–9 as a guide. Reverse procedure to reassemble, using the same Figure 6–9 as a guide. Figure 6–9: Disassembly of Front-Panel Assembly 5. Reinstallation: If the front-panel assembly was further disassembled in step 4, then reverse substeps 4a–4c to reassemble, using Figure 6–9 as a guide. Then do step 3, reversing the procedure outlined in each substep.
Removal and Installation Procedures 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 Buttons, and Attenuator Panel (page 6–22) to remove the front cover and trim ring. b. Lift the front-panel assembly out of the front subpanel until you can reach J2 on the front-panel assembly.
Removal and Installation Procedures c. Repeat procedure to remove the remaining cap as needed; push the cap(s) back on to reinstall. 5. Remove the flip stand: Grasp the flip stand by both sides near where it joins each flip stand foot. Now compress the flip stand until the flip stand ends clear the flip stand feet to complete the removal. 6. Remove the flip stand foot (or feet): a. Do Rear Cover and Cabinet procedure (page 6–18) to gain access to inside of the cabinet. b.
Removal and Installation Procedures Push down to flex handle and flatten against cabinet; then pull it out.
Removal and Installation Procedures Procedures for Outer-Chassis Modules You should have completed the Access Procedure before doing any procedure in this collection. The procedures found here, listed in order presented, follow. Fan H Fan H A14 D1 Bus and Analog-Power and Digital-Power Cables H A23 SerPar Board H A29 Video Trigger Board H A11 Processor/Display Board H Top Cover and Board Brackets H Rear-Panel Cables H A10 Acquisition Board H Rear Chassis 1.
Removal and Installation Procedures processor/display board; J100 is on the acquisition board.) Reverse these removal instructions to reinstall. 4. Remove the analog-power and digital-power interconnect cables: a. Unplug the analog-power cable at J26 on the display processor board, at J5 on the low-voltage power supply, and at J700 on the acquisition board. b. Unplug the digital-power cable at J27 on the display processor board, at J6 on the low-voltage power supply, and at J101 on the acquisition board.
Removal and Installation Procedures A23 SerPar Board — RS232/Centronics Hardcopy Interface 1. Remove circuit board assembly: a. Using a screwdriver with size T-15 TorxR tip, remove the two screws (number 4 in Figure 6–12) securing the rear plate of the circuit board assembly. b. Disconnect the cable connector (number 2) from the processor-display circuit board connector (number 1). c. Pull out the A23 SerPar Board assembly (number 3).
Removal and Installation Procedures b. Separate the circuit board with attached cable (number 1), from the rear plate with attached brackets (number 2). 2 3 1 Figure 6–13: Remove Circuit Board From Assembly 3. Replace circuit board: Equipment Required: One 3@16 inch nutdriver. a. Replace the failed circuit board with a replacement A23 SerPar Board ordered from the factory (see Replaceable Parts List for detailed ordering information).
Removal and Installation Procedures 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 Board on Figure 6–15, page 6–35. c. Do the procedures A14 D1 Bus and Analog-Power and Digital-Power Cables and A23 SerPar Board that precede this procedure to remove those items.
Removal and Installation Procedures Coax Cable Figure 6–14: Circuit Board Installed 6–34 TDS 684A, TDS 744A, & TDS 784A Service Manual
Removal and Installation Procedures Coax Cable To J1500 1 2 3 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 Board. NOTE. For the TDS 684A, be sure to arrange the coax cable as shown in Figures 6–14 and 6–15. Failure to do this may impair performance. Also, when plugging in the digital bus boards, 1 and 3 in Figure 6–15, make sure that they remain plugged in on both ends.
Removal and Installation Procedures 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 and Cabinet (page 6–18) to complete reassembly of the oscilloscope. c. To ensure the Video Trigger is working correctly, perform the Diagnostics procedure on page 6–57.
Removal and Installation Procedures installed, A29 Video Trigger Board, and Rear Cover and Cabinet (page 6–18) to complete reassembly of the oscilloscope. J20 J5 J5 J38 J35 J51 J51 J38 J38 J37 J37 J62 J2 J2 To J38 To J20 1 Unplug the cables. To J51 To J37 To J38 To J5 To J62 2 Slide the A11 DRAM Processor/Display board to the rear to release it from the board mounts; then lift up to complete removal. To J2 Figure 6–16: A11 Processor/Display Removal Top Cover and Board Brackets 1.
Removal and Installation Procedures 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-Power Cables (page 6–29), A23 SerPar Board (page 6–31), if option 05 is installed A29 Video Trigger Board (page 6–32) and A11 Processor/Display Board (page 6–36) to remove those modules. 2. Orient the oscilloscope: Set the oscilloscope so its bottom is down on the work surface and its front is facing you. 3.
Removal and Installation Procedures Rear-Panel Cables 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 Front Cover, Trim Ring, Menu Buttons, and Attenuator Panel (page 6–22) H Rear Cover and Cabinet (page 6–18) 1. Assemble equipment and locate modules to be removed: Have handy a pair of needle-nose pliers (Item 6).
Removal and Installation Procedures 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. Remove the Acquisition Board: Use Figure 6–18 as a guide. a. Disconnect the cables from (CH 3) SIGNAL OUT (at J1201), AUX TRIG INPUT (at J1550), MAIN TRIG OUTPUT (at J1000), DELAYED TRIG OUTPUT (at J1001). b.
Removal and Installation Procedures Six Securing Screws A14 D1 Bus AUX MAIN TRIGGER SIGNAL TRIGGER INPUT OUTPUT OUTPUT DELAYED TRIGGER OUTPUT Digital Power Cable Analog Power Cable J1500 J1201J1100 J1550 J1000 J1001 Five Securing Screws Figure 6–18: A10 Acquisition Board Removal TDS 684A, TDS 744A, & TDS 784A Service Manual 6–41
Removal and Installation Procedures Floppy Disk 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 the locator diagram Outer-Chassis Modules, Figure 6–2, page 6–13. 2. Do the procedure Front Cover, Trim Ring, Menu Buttons, and Attenuator Panel (page 6–22) 3.
Removal and Installation Procedures 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, to complete reassembly of the oscilloscope: H Front Cover, Trim Ring, Menu Buttons, and Attenuator Panel (page 6–22). H Rear Cover and Cabinet (page 6–18).
Removal and Installation Procedures Rear Chassis 1. Assemble equipment and locate modules to be removed: a. Have handy a screwdriver with a size T-15 TorxR tip (Items 1 and 2). b. Locate the modules to be removed, including those listed under Additional Modules Removed in the locator diagram Outer-Chassis Modules, Figure 6–2, page 6–13. c. Install the front cover if it’s not already installed. 2.
Removal and Installation Procedures DELAY TRIGGER to J1001 MAIN TRIGGER to J1000 AUXILIARY TRIGGER to J1550 CH3 OUT to J1201 EMI Gaskets Figure 6–20: Rear Chassis Removal TDS 684A, TDS 744A, & TDS 784A Service Manual 6–45
Removal and Installation Procedures Procedures for Inner-Chassis Modules You should have completed the Access Procedure (page 6–15) before doing any of the procedures for the Inner-Chassis modules. The procedures are presented in the following order: A16 Low Voltage Power Supply A30 Display Assembly and Supply Fuse Front Subpanel Main Chassis A16 Low Voltage Power Supply 1. Assemble equipment and locate modules to be removed: Have handy a screwdriver with a size T-15 TorxR tip (Items 1 and 2).
Removal and Installation Procedures 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 board upward as indicated to clear the lip of the main chassis when lifting this board out. Figure 6–21: A16 Low Voltage Power Supply Removal A30 Display Assembly and Supply Fuse NOTE. The display and the display-driver board are a single module and must be removed and replaced as such.
Removal and Installation Procedures 1. Assemble equipment and locate modules to be removed: Have handy a screwdriver with a size T-15 TorxR tip (Items 1 and 2). Locate the modules to be removed in the locator diagram Inner-Chassis Modules, Figure 6–2, page 6–13. 2. Orient the oscilloscope: Set the oscilloscope so its bottom is down on the work surface and its rear is facing you. 3. Remove the high-voltage fuse: If you are servicing this fuse, remove the fuse from its fuse holder.
Removal and Installation Procedures e. Be sure you have read the WARNING on display tube handling and storage found at the start of this display tube removal procedure. Then pull the display tube out through the front subpanel to complete removal. Store as directed in the previous WARNING message. J305 J350 J570 J170 Figure 6–22: Display Assembly Removal 5. Remove the display supply board: Use Figure 6–23 as a guide. CAUTION.
Removal and Installation Procedures 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 the top of the oscilloscope’s main chassis. Move circuit board forward to clear main chassis. Figure 6–23: Display Driver Board Removal 6. Reinstallation: a. Do, in reverse order, substeps 5a–5b, reversing each step to reinstall Display-Driver board. b.
Removal and Installation Procedures Front Subpanel 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-Power Cables (page 6–29) H Display-Frame Assembly H Front Cover, Trim Ring, Menu Buttons, and Attenuator Panel (page 6–22) H Rear Cover and Cabinet (page 6–18) (completes reassembly) 1.
Removal and Installation Procedures 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 Removal Main Chassis Additional Modules Removed: All. 1. Remove the main chassis: Since the removal of the main chassis requires the removal of virtually all modules, do the procedure Disassembly for Cleaning that follows.
Removal and Installation Procedures Disassembly for Cleaning This procedure is for disassembly of the Digitizing Oscilloscopes into its individual modules so they can be cleaned. For the cleaning instructions, see Inspection and Cleaning, which begins this section. 1. Assemble equipment and locate modules to be removed: a. Have handy a screwdriver with a size T-15 TorxR tip (Items 1 and 2), a T-20 TorxR tip (Item 3), a flat-bladed screwdriver (Item 6–11), and a pair of angle-tip tweezers (Item 6–11). b.
Removal and Installation Procedures 5. Disassemble the chassis: a. Set the assembly so its bottom is down on the work surface and its front is facing you. b. Remove the six screws securing the front subpanel to the main chassis. (See Figure 6–24 for screw location.) c. Lift the front subpanel up away from the main chassis. d. Now remove the five screws securing the rear chassis to the main chassis and separate the two chassis. (See Figure 6–20 for screw location.) 6.
Removal and Installation Procedures H A10 Acquisition Board (page 6–39) d. Reinstall external modules: Do in the order listed the following procedures. When doing these procedures, do the steps in reverse order. These procedures are found under Procedures for External Modules which starts on page 6–16.
Removal and Installation Procedures 6–56 TDS 684A, TDS 744A, & TDS 784A Service Manual
Troubleshooting This subsection contains information and procedures designed to help you isolate faulty modules in the oscilloscope. If a module needs to be replaced, follow the Removal and Installation Procedures located in this section. Diagnostics The oscilloscope has two levels of internal diagnostics that focus on verifying, adjusting, and if need be, isolating faulty modules. Both levels of internal diagnostics report any bad modules and/or interfaces.
Troubleshooting Firmware Updates Digitizing Oscilloscopes firmware updates are easy to do. Simply install the firmware disks on your PC and follow the instructions in the README file located on the first disk. NOTE. You must set the Protection switch to the unprotected position before updating the Firmware. Figure 6–25 shows how to set the switch. After loading the Firmware, be sure you set the switch back to the protected position and cycle power.
Troubleshooting Press on the principal power switch on the back of the oscilloscope. Can you hear the fan whirling? Press the ON/STBY button. Can you hear the fan now? No Yes Yes When the oscilloscope powers on, do the frontpanel lights come on and then go off about 30 seconds later? Yes Does the display seem to be working at all? No Power off and remove the cover using the Rear Cover and Cabinet removal procedure.
Troubleshooting Power on again and observe the LED ( DS1). Does it display .E? Yes No Is there~0 V on J26 Pin 4? (See Figure 6–32.) Yes Power on again and observe the LED (DS1). Does it only display .8? No Yes Is there 5.1 V on J27 pin 17? (See Figure 6–32.) Yes Replace the A11 DRAM Processor/Display module.! No Perform the A16 Low Voltage Power Supply Module Isolation troubleshooting procedure.! Replace the A17 Main LV Power Supply module.
Troubleshooting This procedure assumes that the oscilloscope is up and running and you can read the display. Does the display report any errors? 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). No Yes Are any failures reported? No The oscilloscope is ok.
Troubleshooting Does the oscilloscope power on, all the diagnostics pass, but sometime later it powers off on its own? Use this procedure to determine if an oscilloscope problem is caused by the Low Voltage Power Supply. Connect the oscilloscope to the correct power source. Turn on the principal power switch. Yes The oscilloscope may have powered off because it over-heated. Wait 5 minutes and power on the oscilloscope. No Are the front-panel lights on? Yes No Press the ON/STBY button.
Troubleshooting Table 6–5: Normal Supply Voltages (Measured on J26 and J27 on the A11 DRAM Processor/Display Module) Supply Lower Limit Upper Limit +5.1 VA (J27 pin 5) +5.0 V +5.2 V +5.1 VB (J27 pin 17) +5.0 V +5.2 V +25 V (J27 pin 1) +23.5 V +27.5 V +5 V (J26 pin 39) +4.9 V +5.1 V –5.1 V (J26 pin 17) –4.9 V –5.2 V +15 V (J26 pin 11) +14.7 V +15.3 V –15 V (J26 pin 7) –14.7 V –15.
Troubleshooting This procedure helps you determine whether the color display or the A11 DRAM Processor/Display module is bad. Do J18 pins 1 and 2 on the A11 DRAM Processor/Display module (see Figure 6–38) have signals similar to Figure 6–31? Is the display Yes legible but the horizontal and/or vertical sync do not look ok? No Replace the A30 Display Assembly. No Power the oscilloscope off and disconnect the cable from J5 on the A11 DRAM Processor/Display module (see Figure 6–38) then power back on.
Troubleshooting J18 pin 1 (Horizontal Sync) J18 pin 2 (Vertical Sync) Figure 6–31: Horizontal and Vertical Sync Signals – Color Display White Level J62 pin 1 (Video) Black Levels Blanking Levels Figure 6–32: A Video Signal with White, Black, and Blanking Levels – Color Display TDS 684A, TDS 744A, & TDS 784A Service Manual 6–65
Troubleshooting This procedure helps you determine whether the A10 Acquisition or the A11 DRAM Processor/Display module is bad. Replace the A14 D1 Bus module. Be sure you connect the A14 D1 Bus module correctly (the silkscreen on the module will help you correctly orient the 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? Yes Done.
Troubleshooting This procedure helps you determine if the A11 DRAM Processor/Display or the A12 Front Panel module is bad. Is the cable from the A11 DRAM Processor/Display module to the A12 Front Panel module securely connected? No Connect the cable and then perform the Primary troubleshooting procedure. Yes Is the ON/STBY button working correctly? On the A11 DRAM Processor/Display No module probe J26 pins 3 and 5 with an ohm meter (see Figure 6–36).
Troubleshooting 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 on the display. Do this for all the channels. For all the channels, is the signal on the display a 1 kHz 0.250 V square wave? No Do all the channels display defective waveforms? No Set all the channels to the same vertical scale and select a channel that works correctly.
Troubleshooting CAUTION. Only probe points specified in the procedures. You can cause catastrophic damage if you attempt to probe other points.
Troubleshooting Pin 100 U2000 U1331 J28 U2001 Pin 1 Pin 3 Pin 17 J27 Pin 3 Pin 4 Pin 5 U1097 J26 J2 S1002 J30 Figure 6–36: A11 DRAM Processor/Display Module (View of Right Side) 6–70 TDS 684A, TDS 744A, & TDS 784A Service Manual
Troubleshooting J35 J20 U174 Figure 6–37: A11 DRAM Processor/Display Module (View of Upper Left Corner) Y3 J5 U190 J62 J18 Figure 6–38: A11 DRAM Processor/Display Module (View of Lower Left Corner) TDS 684A, TDS 744A, & TDS 784A Service Manual 6–71
Troubleshooting U1001 U1540 U604 Pin 5 Pin 7 Pin 9 Pin 11 Figure 6–39: A10 Acquisition Module (View of Lower Right Corner) 6–72 TDS 684A, TDS 744A, & TDS 784A Service Manual
Options and Accessories This section describes the various options as well as the standard and optional accessories that are available for the TDS 684A and 7XXA Oscilloscope.
Options and Accessories Table 7–1: Options (Cont.) 7–2 Option # Label Description 1M (TDS 7XXA) 130,000 record length (TDS 7XXA) Extend TDS 7XXA record length from 50,000 standard to 500,000 samples on one channel, 250,000 on two channels, and 130,000 samples on three or four channels. 1R Rackmount Oscilloscope comes configured for installation in a 19 inch wide instrument rack. For later field conversions, order kit # 016-1236-00.
Options and Accessories Table 7–1: Options (Cont.) Option # Label 95 Calibration Data Report 96 Calibration Certificate Description Certificate of Calibration which states this instrument meets or exceeds all warranted specifications and has been calibrated using standards and instruments whose accuracies are traceable to the National Institute of Standards and Technology, an accepted value of a natural physical constant, or a ratio calibration technique.
Options and Accessories Optional Accessories You can also order the optional accessories listed in Table 7–3.
Options and Accessories Accessory Software H AM 503S — DC/AC Current probe system, AC/DC. Uses A6302 Current Probe. H AM 503S Option 03: DC/AC Current probe system, AC/DC. Uses A6303 Current Probe. H P6021 AC Current probe. 120 Hz to 60 MHz. H P6022 AC Current probe. 935 kHz to 120 MHz. H CT-1 Current probe — designed for permanent or semipermanent in-circuit installation. 25 kHz to 1 GHz, 50 W input. H CT-2 Current probe — designed for permanent or semipermanent in-circuit installation. 1.
Options and Accessories H 7–6 CALXXXX provides one year of calibration support. It is available in one year increments up to five years.
Electrical Parts List The modules that make up this instrument are often a combination of mechanical and electrical subparts. Therefore, all replaceable modules are listed in Section 10, Mechanical Parts List. Refer to that section for part numbers when using this manual.
Electrical Parts List 8–2 TDS 684A, TDS 744A, & TDS 784A Service Manual
Diagrams This contains the block diagram and the interconnection diagram for the TDS 684A and 7XXA Digitizing Oscilloscopes. Symbols Graphic symbols and class designation letters are based on ANSI Standard Y32.2–1975. Abbreviations are based on ANSI Y1.1–1972. Logic symbology is based on ANSI/IEEE Std 91-1984 in terms of positive logic. Logic symbols depict the logic function performed and can differ from the manufacturer’s data.
Diagrams 26 A12 Front Front Panel Switches Menu Switches Front Panel Knobs 10 A10 Acquisition P2 Panel Board P3 Board PD1 SIGNAL PD2 GND 15 Pins Flex J1201 J1550 J1000 J1001 J1153 CH 1 J1002 NC J1003 NC Attenuator CH 2 CH 3 J102 CH 4 100 J100 J101 50 J1500 A18 Main Converter Control Board P7 12 A17 Control Board P6 12 J4 Main LV Power Supply Board J1 A19 Power Factor J2 J5 J6 Analog Power 40 40 Digital Power A Filter A29 J6 Video Trigger Board (Option 05) J3 J2 J
Diagrams SIGNAL OUTPUT AUX TRIGGER INPUT MAIN TRIGGER OUTPUT DELAYED TRIGGER OUTPUT A11 Dram J2 Fan J20 15 J51 J40 J37 GPIB IEEE STD 488 PORT 15 PIN VGA ANALOG OUTPUT 26 Processor J35 Display Board 20 Cartridge Console Service Port A23 Serpar Board P1 20 A30 Display Board 100 P100 NC P28 100 J28 J30 J5 16 J390 2 Vert Yoke A32 Video J150 J285 2 Board J455 J501 J530 Floppy Driver 26 40 40 J62 P38 J26 2 J400 J60 J70 J280 J150 J300 J500–1 J500–2 J500–3 J500–4 J500–5 J90 J100
Diagrams A10 Acquisition CH 1 CH 2 CH 3 Attenuator CH 4 A29 Triggers Video Trigger (Option 05) 100 A14 D1 Bus 100 A/D Converters 100 A12 Front Panel Menu Switches 10 25 Front Panel Switches ON/STBY Front Panel LEDS ~PF ON/STBY Front Panel Pots SIGNAL Probe Compensation GND Low Voltage Power Supply J1 Filter 40 Power to All Circuits Floppy Driver 26 A17 Main LV Power Supply A18 Main Converter Control A19 Power Factor Control Figure 9–2: Block Diagram 9–4 TDS 684A, TDS 744A,
Diagrams SIGNAL OUTPUT AUX TRIGGER INPUT MAIN TRIGGER OUTPUT DELAYED TRIGGER OUTPUT A27 100 A11 Dram Processor/ Connector (Option 05) FAN GPIB IEEE STD 488 PORT 15 PIN VGA ANALOG OUTPUT 26 Display 15 Processor System 100 CENTRONIICS COMPATIBLE A23 Serpar 26 RS-232 A30 Display Driver CRT Anode 2 D2 BUS 68020 BUS Vert Yoke A32 Video VIDEO ~FSYNC/ VIDEO Display System GRID1,2 J530 FOCUS 6 ~VSYNC V1000 ~HSYNC 26 2 ~FSYNC/ VIDEO Horiz Yoke A31 Shutter J505 LCS CLK J560 Driver J57
Diagrams 9–6 TDS 684A, TDS 744A, & TDS 784A Service Manual
Mechanical Parts List This section contains a list of the replaceable modules for the oscilloscope. Use this list to identify and order replacement parts. Parts Ordering Information Replacement parts are available through your local Tektronix field office or representative. Changes to Tektronix instruments are sometimes made to accommodate improved components as they become available and to give you the benefit of the latest circuit improvements.
Mechanical Parts List Using the Replaceable Parts List This section contains a list of the mechanical and/or electrical components that are replaceable for the oscilloscope. Use this list to identify and order replacement parts. The following table describes each column in the parts list. Parts List Column Descriptions Column Column Name Description 1 Figure & Index Number Items in this section are referenced by component number.
Mechanical Parts List Manufacturers Cross Index Mfr. Code Manufacturer Address City, State, Zip Code S3109 FELLER 72 VERONICA AVE UNIT 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.
Mechanical Parts List Manufacturers Cross Index (Cont.) Mfr.
Mechanical Parts List This page intentionally left blank.
Mechanical Parts List Replaceable Parts List Fig. & Index Number Tektronix Part Number 1–1 200–3695–02 –2 161–0230–01 –3 –4 Name & Description Mfr. Code Mfr.
Mechanical Parts List 1 2 3 4 5 7 8 13 9 10 11 6 12 20 19 13 18 17 16 15 14 21 22 23 A12 Figure 10–1: External Modules TDS 684A, TDS 744A, & TDS 784A Service Manual 10–7
Mechanical Parts List Replaceable Parts List Fig. & Index Number Tektronix Part Number 2–1 212–0189–00 –2 119–4615–00 –3 Serial No. Effective Serial No. Discont’d Name & Description Mfr. Code Mfr. Part Number 6 SCR,ASSEM WSHR:8–32 X 0.
Mechanical Parts List 2 1 10 9 A11 4 3 8 5 7 11 10 12 6 12 19 18 17 16 13 A14 15 14 A10 Figure 10–2: Outer-Chassis Modules TDS 684A, TDS 744A, & TDS 784A Service Manual 10–9
Mechanical Parts List Replaceable Parts List Fig. & Index Number Tektronix Part Number 3–1 640–0077–04 –2 348–1300–00 –3 Serial No. Effective Serial No. Discont’d Name & Description Mfr. Code Mfr. Part Number 1 DISPLAY MODULE:TDS FAMILY FULL COLOR 80009 640–0077–03 2 SHLD,GSKT,ELEK:3.165 L,CLIP ON 30817 0098–0564–09–03 620–0063–02 1 POWER SUPPLY:400W;5V 12A,5.1V 22A,15V 1,5A (A16,EXCHANGE ITEM) 1GM54 620–0063–02 –4 441–2043–00 1 CHASSIS,SCOPE:MAIN,0.
Mechanical Parts List Replaceable Parts List Fig. & Index Number Tektronix Part Number 4–1 174–2031–00 Serial No. Effective Serial No. Discont’d Qty Name & Description 4 CABLE ASSY,RF:50 OHM COAX,6.5 L,W/BLUE JKT (A10J1000 MAIN TO TRIGGER OUTPUT) (A10J1001 TO DELAYED TRIGGER OUTPUT) Mfr. Code Mfr.
Mechanical Parts List Replaceable Parts List Fig. & Index Number Tektronix Part Number 5–1 174–1525–00 –2 174–1524–00 129–1439–00 –3 Serial No. Effective Serial No. Discont’d Name & Description Mfr. Code Mfr. Part Number 1 CA ASSY,SP,ELEC:2 X 8–13,28 AWG TK2469 ORDER BY DESC 1 2 CA ASSY SP:RIBBON,GPIB;IDC,24,28 AWG,4.0L SPACER,POST:0.17 L,4–40 BRS,0.
Mechanical Parts List 2 3 1 4 5 7 6 Figure 10–5: Cables, Top View TDS 684A, TDS 744A, & TDS 784A Service Manual 10–13
Mechanical Parts List Replaceable Parts List Fig. & Index Number Tektronix Part Number 6–1 119–4547–00 1 DISK DRIVE:FLOPPY,3.5 INCH;2MB,0.5 INH DSDD TK2248 119–4547–00 –2 211–0840–00 2 SCREW,MACHINE:M2.6 X 0.45MM PITCH X 4.0 L 0KB01 .26C4MXPHY –3 211–0730–00 2 SCR,ASSEM WSHR:6–32 X 0.375,PNH,STL 0KB01 ORDER BY DESC –4 174–2964–00 276–0849–00 1 1 WIRE,ELECTRICAL:FLAT FLEX,JUMPER CORE,EM:EMI SUPPRESS,RBN CA 1DM20 1JJ96 1.00MM–26–7–B BFS 33.
Mechanical Parts List 3 4 2 1 6 5 Figure 10–6: Floppy Disk TDS 684A, TDS 744A, & TDS 784A Service Manual 10–15
Mechanical Parts List Replaceable Parts List Fig. & Index Number Tektronix Part Number 7–1 Serial No. Effective Serial No. Discont’d Mfr. Code Mfr. Part Number CA ASSY,PWR:3,1.0MM SQ,250V/10A,2.5 M (OPTION A3 – AUSTRALIAN) S3109 198–010 1 CA ASSY,PWR:3,1.0MM SQ,250V/10A,2.5 M (OPTION A1 – EUROPEAN) S3109 198–010 161–0104–07 1 CA ASSY,PWR:3,1.0MM SQ,240V/10A,2.
Mechanical Parts List Replaceable Parts List Fig. & Index Number Tektronix Part Number Serial No. Effective Serial No. Discont’d Mfr. Code Mfr.
Mechanical Parts List 10–18 TDS 684A, TDS 744A, & TDS 784A Service Manual
