Tektronix 784A User Manual

Service ManualTDS 684A, TDS 744A, & TDS 784ADigitizing Oscilloscope070-8992-03WarningThe servicing instructions are for use by qualifiedpersonnel

Table of ContentsviTDS 684A, TDS 744A, & TDS 784A Service Manual

Performance Tests4–24TDS 684A, TDS 744A, & TDS 784A Service ManualTDS 7XXA Test Record (Cont.)Instrument Serial Number: Certificate Number:Tempera

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–25TDS 7XXA Test Record (Cont.)Instrument Serial Number: Certificate Number:Tempera

Performance Tests4–26TDS 684A, TDS 744A, & TDS 784A Service ManualTDS 7XXA Test Record (Cont.)Instrument Serial Number: Certificate Number:Tempera

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–27Signal Acquisition System ChecksThese procedures check those characteristics tha

Performance Tests4–28TDS 684A, TDS 744A, & TDS 784A Service Manualb. Set the vertical scale: Set the vertical SCALE to one of the settingslisted i

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–29 Align the active cursorover the waveform.1Read themeasurementresults.2Figure 4–

Performance Tests4–30TDS 684A, TDS 744A, & TDS 784A Service Manual1. Install the test hookup and preset the instrument controls:a. Hook up the tes

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–31a. Select an unchecked channel:H Press WAVEFORM OFF to remove the channel just c

Performance Tests4–32TDS 684A, TDS 744A, & TDS 784A Service ManualH Use the keypad to set vertical offset to the positive-polarity settinglisted i

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–33H Repeat substeps c through f until all vertical scale settings, listed inTable

Table of ContentsTDS 684A, TDS 744A, & TDS 784A Service ManualviiList of TablesTable 1–1: Key Features of the TDS 684A and 7XXA Oscilloscopes 1–1

Performance Tests4–34TDS 684A, TDS 744A, & TDS 784A Service ManualHigh FrequencySine WaveGeneratorDigitizing OscilloscopeOutputLeveling HeadFigure

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–35Table 4–4: Analog Bandwidth Vertical ScaleAttenuators(10X)Reference Amplitude (a

Performance Tests4–36TDS 684A, TDS 744A, & TDS 784A Service Manualf. Measure the test signal:H Set the frequency of the generator, as shown on scr

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–37STOP. Checking each channel’s bandwidth at all vertical scale settings is timeco

Performance Tests4–38TDS 684A, TDS 744A, & TDS 784A Service ManualSTOP. DO NOT use the vertical position knob to reposition any channel whiledoing

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–392. Confirm all four channels (CH 1 through CH 4) are within limits for channelde

Performance Tests4–40TDS 684A, TDS 744A, & TDS 784A Service ManualH Press the main-menu button Function; then press the side-menubutton V Bars.H P

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–41ment column of Table 4–5. Note that these numbers may be eitherpositive or negat

Performance Tests4–42TDS 684A, TDS 744A, & TDS 784A Service ManualTime Base System ChecksThese procedures check those characteristics that relate

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–43H Set the horizontal SCALE of the Main time base to 1 ms.H Press TRIGGER MENU; t

Table of ContentsviiiTDS 684A, TDS 744A, & TDS 784A Service ManualTable 6–2: External Inspection Check List 6–5. . . . . . . . . . . . . . . . .

Performance Tests4–44TDS 684A, TDS 744A, & TDS 784A Service Manual Check long–term samplerates and delay timeaccuracies against limits.4Align the

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–451. Install the test hookup and preset the instrument controls:a. Initialize the

Performance Tests4–46TDS 684A, TDS 744A, & TDS 784A Service Manualb. Set the trigger mode: Press TRIGGER MENU. Now press themain-menu button Mode

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–47Set upperand lowerlimits thatensuretriggering.Then changelimits untiltriggerings

Performance Tests4–48TDS 684A, TDS 744A, & TDS 784A Service ManualH CHECK that the Lower Limit readout, after the oscilloscope stopstriggering, is

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–49H Connect the output of the DC calibration generator, through adual-banana conne

Performance Tests4–50TDS 684A, TDS 744A, & TDS 784A Service Manualc. Read results (Check against limits): See Figure 4–16.H CHECK that the Level r

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–51H Press HORIZONTAL MENU.H Press the main-menu button Time Base.H Press the side-

Performance Tests4–52TDS 684A, TDS 744A, & TDS 784A Service ManualEquipmentRequiredOne medium-frequency leveled sine wave generator (Item 11)One h

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–53the other output of the T connector to the AUX TRIG INPUT at therear panel. See

TDS 684A, TDS 744A, & TDS 784A Service ManualixGeneral Safety SummaryReview the following safety precautions to avoid injury and prevent damage to

Performance Tests4–54TDS 684A, TDS 744A, & TDS 784A Service Manualtriggered on the selected slope (positive or negative). This displayshould not h

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–55c. Check Delayed trigger system for stable triggering at limits: Do thefollowing

Performance Tests4–56TDS 684A, TDS 744A, & TDS 784A Service ManualH Press SET LEVEL TO 50%. CHECK that a stable trigger isobtained for the test wa

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–57NOTE. You just checked the trigger sensitivity. If desired, you may repeat steps

Performance Tests4–58TDS 684A, TDS 744A, & TDS 784A Service ManualH Press save/recall SETUP.H Press the main-menu button Recall Factory Setup.H Pr

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–59Check outputFigure 4–20: Measurement of Main Trigger Out Limitsd. Check Delayed

Performance Tests4–60TDS 684A, TDS 744A, & TDS 784A Service ManualH Press the main-menu button Source.H Press the side-menu button Ch3.H Set verti

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–611. Install the test hookup and preset the instrument controls: a. Hook up test-s

Performance Tests4–62TDS 684A, TDS 744A, & TDS 784A Service ManualH Select 128 averages.2. Confirm that the Probe Compensator signal is within lim

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–63H Press SAVE/RECALL WAVEFORM; then press the main-menubutton Save Wfm Ch 1.H Pre

General Safety SummaryxTDS 684A, TDS 744A, & TDS 784A Service ManualBefore applying power, ensure that the line selector is in the proper position

Performance Tests4–64TDS 684A, TDS 744A, & TDS 784A Service ManualH Adjust the output of the DC calibration generator until it preciselyoverlaps t

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–65Option 05 Video Trigger ChecksEquipmentRequiredPAL signal source (Item 16)60 Hz.

Performance Tests4–66TDS 684A, TDS 744A, & TDS 784A Service Manualg. Press the main-menu Bandwidth.h. Select 250 MHz from the side menu.i. Press t

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–67Figure 4–26: Jitter Test Displayed Waveform – TDS 684A Shownc. Press SHIFT; then

Performance Tests4–68TDS 684A, TDS 744A, & TDS 784A Service Manualq. Press the main-menu Mode.r. Press the side-menu Envelope.s. Use the keypad to

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–69b. Press WAVEFORM OFF.c. Press HORIZONTAL MENU.d. Use the keypad to set horizont

Performance Tests4–70TDS 684A, TDS 744A, & TDS 784A Service ManualPositive pulseNegative pulsesFigure 4–28: Triggered Signal Range Test – 300 mVn.

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–71Positive pulseNegative pulsesFigure 4–29: Triggered Signal Range Test – 75 mVp.

Performance Tests4–72TDS 684A, TDS 744A, & TDS 784A Service ManualDigitizing Oscilloscope50  CableSignal GeneratorOutputFigure 4–30: 60 Hz Reject

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–73COMPST on the TSG 121) to a 75 W cable and a 75 W terminator.Connect both signal

General Safety SummaryTDS 684A, TDS 744A, & TDS 784A Service ManualxiThe following symbols may appear on the product: DANGERHigh VoltageProtective

Performance Tests4–74TDS 684A, TDS 744A, & TDS 784A Service ManualFigure 4–33: 60 Hz Rejection Test Result – TDS 684A Shown6. Check Line Count Acc

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–75PAL SignalSourceDigitizing Oscilloscope75  Cable75 TerminatorOutputFigure 4–34

Performance Tests4–76TDS 684A, TDS 744A, & TDS 784A Service ManualFigure 4–35: Line Count Accuracy Test Setup Waveform – TDS 684A ShownH Press CUR

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–77Figure 4–36: Line Count Accuracy Correct Result WaveformH Disconnect all test eq

Performance Tests4–78TDS 684A, TDS 744A, & TDS 784A Service ManualH Press the side-menu Fields.H Use the keypad to set the number of fields to 1 (

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–79c. Check Sync Duty Cycle.H Connect the pulse generator (PG502) through a 50 W ca

Performance Tests4–80TDS 684A, TDS 744A, & TDS 784A Service ManualFigure 4–38: Sync Duty Cycle Test: One-Div Neg Pulse WaveformH Turn the pulse ge

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–81Figure 4–39: Sync Duty Cycle Test: Critically Adjusted PulseH Press TRIGGER MENU

Performance Tests4–82TDS 684A, TDS 744A, & TDS 784A Service ManualH Disconnect the signal source from CH1, wait a few seconds, thenreconnect the s

General Safety SummaryxiiTDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual5–1Adjustment ProceduresThis section contains information needed to adjust the TDS 684A and 7XXA Digi

Adjustment Procedures5–2TDS 684A, TDS 744A, & TDS 784A Service ManualTwo small holes in the chassis allow service personnel to insert a tool and p

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–3Since the display-assembly and P6139A probe adjustment require manualadjustme

Adjustment Procedures5–4TDS 684A, TDS 744A, & TDS 784A Service ManualAfter the removal and replacement of a module due to electrical failure, youm

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–5Equipment RequiredTable 5–4 lists the test equipment required to adjust the T

Adjustment Procedures5–6TDS 684A, TDS 744A, & TDS 784A Service ManualTable 5–4: Test Equipment, Fixtures, and Supplies (Cont.)Item Number andDescr

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–7Adjustment InstructionsThe following instructions describe installing the sof

Adjustment Procedures5–8TDS 684A, TDS 744A, & TDS 784A Service Manual2. Install the software to hard disk:a. Install your working disk in a floppy

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–9d. Follow the instructions as prompted on your computer screen. This willincl

Adjustment Procedures5–10TDS 684A, TDS 744A, & TDS 784A Service ManualCAUTION. Be sure to disable the NVRAM Protection switch as instructed belowt

TDS 684A, TDS 744A, & TDS 784A Service ManualxiiiService Safety SummaryOnly qualified personnel should perform service procedures. Read this Servi

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–11Figure 5–2: Hookup for Probe Compensationa. Hook up test-signal source: Inst

Adjustment Procedures5–12TDS 684A, TDS 744A, & TDS 784A Service ManualFigure 5–3: Performing Probe Compensation2. Compensate the Probe:a. Locate t

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–133. Disconnect the hookup: Disconnect the probe from the probe compensatorter

Adjustment Procedures5–14TDS 684A, TDS 744A, & TDS 784A Service ManualDigitizing OscilloscopeBNC-Female-to-Female BNCAdapterLeveling HeadBNC-to Pr

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–15a. Display and measure the test signal:H Monitor the CH 1 Pk-Pk readout whil

Adjustment Procedures5–16TDS 684A, TDS 744A, & TDS 784A Service Manuala. Access Inner Probe Tip and Adjustment Ports:H The probe tip should be exp

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–17Digitizing OscilloscopeCalibrationGeneratorTunnel Diode Pulser10X Attenuator

Adjustment Procedures5–18TDS 684A, TDS 744A, & TDS 784A Service ManualH Press SHIFT; then press ACQUIRE MENU.H Press the main-menu button Mode. Th

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–19LF CompR1 R2C1Not UsedFigure 5–9: Locations of P6139A Probe AdjustmentsH See

Adjustment Procedures5–20TDS 684A, TDS 744A, & TDS 784A Service Manual5 nsC120 nsR110 nsR2Adjust R1 for best overall match.1Adjust R2 and C1 for b

Service Safety SummaryxivTDS 684A, TDS 744A, & TDS 784A Service Manual

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–21Display Assembly AdjustmentSTOP. It is not necessary to do this procedure to

Adjustment Procedures5–22TDS 684A, TDS 744A, & TDS 784A Service Manual3. Adjust the display brightnessH Locate R403 (BRIGHTNESS). It is one of the

Adjustment ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual5–23H Press the main-menu button EXECUTE; then press the side-menubutton Ok Conf

Adjustment Procedures5–24TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual6–1MaintenanceThis section contains the information needed to do periodic and correctivemaintenance o

Maintenance6–2TDS 684A, TDS 744A, & TDS 784A Service ManualH Section 10, Mechanical Parts List, lists all field replaceable modules by partnumber.

MaintenanceTDS 684A, TDS 744A, & TDS 784A Service Manual6–3Table 6–1: Relative Susceptibility to Static-Discharge Damage Semiconductor ClassesRela

Maintenance6–4TDS 684A, TDS 744A, & TDS 784A Service ManualInspection and CleaningInspection and Cleaning describes how to inspect for dirt and da

MaintenanceTDS 684A, TDS 744A, & TDS 784A Service Manual6–5Table 6–2: External Inspection Check List Item Inspect For Repair ActionCabinet, front

TDS 684A, TDS 744A, & TDS 784A Service ManualxvPrefaceThis preface contains information needed to properly use this manual to servicethe TDS 684A

Maintenance6–6TDS 684A, TDS 744A, & TDS 784A Service ManualCAUTION. To prevent damage from electrical arcing, ensure that circuit boardsand compon

MaintenanceTDS 684A, TDS 744A, & TDS 784A Service Manual6–7STOP. If, after doing steps 1 and 2, a module is clean upon inspection, skip theremaini

Maintenance6–8TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual6–9Removal and Installation ProceduresThis subsection contains procedures for removal and installatio

Removal and Installation Procedures6–10TDS 684A, TDS 744A, & TDS 784A Service ManualSTOP. READ THESE GENERAL INSTRUCTIONS BEFORE REMOVING AMODULE.

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–11tool whenever a procedure step instructs you to remove or inst

Removal and Installation Procedures6–12TDS 684A, TDS 744A, & TDS 784A Service ManualLine CordFuse CapHandleTrim RingFront PanelKnobsFront CoverLin

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–13Analog and DigitalPower CablesA14 D1 BusRear ChassisFanA10 Acq

Removal and Installation Procedures6–14TDS 684A, TDS 744A, & TDS 784A Service ManualA16 Power SupplyFront SubpanelA30 DisplayAssemblyMain ChassisF

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–15Access ProcedureBegin with this procedure when you have identi

Copyright  Tektronix, Inc. 1994, 1995. All rights reserved.Tektronix products are covered by U.S. and foreign patents, issued and pending. Informatio

PrefacexviTDS 684A, TDS 744A, & TDS 784A Service ManualH Diagrams contains a block diagram and an interconnection diagram usefulfor isolating fail

Removal and Installation Procedures6–16TDS 684A, TDS 744A, & TDS 784A Service Manualc. Do, in the order listed, the three procedures A14 D1 Bus an

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–17When reinstalling theknobs, note there are threesizes. Be sure

Removal and Installation Procedures6–18TDS 684A, TDS 744A, & TDS 784A Service Manual5. Reinstallation: Do in reverse steps 3 and 4 to reinstall th

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–193. Disconnect the line cord: Unplug the line cord from its rec

Removal and Installation Procedures6–20TDS 684A, TDS 744A, & TDS 784A Service Manualb. Take care not to bind or snag the cabinet on internal cabli

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–21Figure 6–6: Rear Cover and Cabinet Removal

Removal and Installation Procedures6–22TDS 684A, TDS 744A, & TDS 784A Service Manual1. Assemble equipment and locate modules to be removed: No too

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–234. Remove the trim ring: Grasp the trim ring by its top edge a

Removal and Installation Procedures6–24TDS 684A, TDS 744A, & TDS 784A Service ManualFront-Panel AssemblyBack ofFront–PanelAssemblyGroundGroundP2P2

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–25c. Now hand disassemble the front-panel assembly components us

PrefaceTDS 684A, TDS 744A, & TDS 784A Service ManualxviiTDS Family (400, 5XXA, 6XXA, and 7XXA) Programmer Manual (Tektronix partnumber 070-8709-XX

Removal and Installation Procedures6–26TDS 684A, TDS 744A, & TDS 784A Service Manual2. Orient the oscilloscope: Set the oscilloscope so its bottom

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–27c. Repeat procedure to remove the remaining cap as needed; pus

Removal and Installation Procedures6–28TDS 684A, TDS 744A, & TDS 784A Service ManualHandle RemovalFlip StandRemovalFoot RemovalHandle CapRemovalP

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–29Procedures for Outer-Chassis ModulesYou should have completed

Removal and Installation Procedures6–30TDS 684A, TDS 744A, & TDS 784A Service Manualprocessor/display board; J100 is on the acquisition board.) Re

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–311. Remove circuit board assembly:a. Using a screwdriver with s

Removal and Installation Procedures6–32TDS 684A, TDS 744A, & TDS 784A Service Manualb. Separate the circuit board with attached cable (number 1),

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–33b. Locate the modules to be removed in the locator diagram Out

Removal and Installation Procedures6–34TDS 684A, TDS 744A, & TDS 784A Service Manual Coax CableFigure 6–14: Circuit Board Installed

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–35 123To J1500 Coax CableFigure 6–15: Circuit Board Removal4. R

PrefacexviiiTDS 684A, TDS 744A, & TDS 784A Service Manual

Removal and Installation Procedures6–36TDS 684A, TDS 744A, & TDS 784A Service Manualb. See the procedures A14 D1 Bus and Analog-Power and Digital-

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–37installed, A29 Video Trigger Board, and Rear Cover and Cabinet

Removal and Installation Procedures6–38TDS 684A, TDS 744A, & TDS 784A Service Manualb. Locate the modules to be removed in the locator diagram Out

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–39H A11 Processor/Display Board (page 6–36)H If option 05 is ins

Removal and Installation Procedures6–40TDS 684A, TDS 744A, & TDS 784A Service Manuald. Do the procedure Front Cover, Trim Ring, Menu Buttons, and

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–41MAINTRIGGEROUTPUTDELAYEDTRIGGEROUTPUTAUXTRIGGERINPUTSIGNALOUTP

Removal and Installation Procedures6–42TDS 684A, TDS 744A, & TDS 784A Service Manual1. Assemble equipment and locate modules to be removed:a. Have

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–43J38Figure 6–19: Floppy Disk Removal5. Reinstallation: Do, in r

Removal and Installation Procedures6–44TDS 684A, TDS 744A, & TDS 784A Service Manual1. Assemble equipment and locate modules to be removed:a. Have

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–45CH3 OUT to J1201AUXILIARY TRIGGER to J1550MAIN TRIGGER to J100

TDS 684A, TDS 744A, & TDS 784A Service ManualxixIntroductionService StrategySTOP. Throughout this manual, any field-replaceable component, assembl

Removal and Installation Procedures6–46TDS 684A, TDS 744A, & TDS 784A Service ManualProcedures for Inner-Chassis ModulesYou should have completed

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–47H A14 D1 Bus and Analog-Power and Digital-Power Cables (page 6

Removal and Installation Procedures6–48TDS 684A, TDS 744A, & TDS 784A Service Manual1. Assemble equipment and locate modules to be removed: Have h

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–49e. Be sure you have read the WARNING on display tube handling

Removal and Installation Procedures6–50TDS 684A, TDS 744A, & TDS 784A Service Manualb. Grasp the display driver board. Work from the front and top

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–51H Top Cover and Board Brackets (top cover only) on page 6–37H

Removal and Installation Procedures6–52TDS 684A, TDS 744A, & TDS 784A Service ManualH A14 D1 Bus and Analog-Power and Digital-Power Cables(page 6–

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–53Disassembly for CleaningThis procedure is for disassembly of t

Removal and Installation Procedures6–54TDS 684A, TDS 744A, & TDS 784A Service Manual5. Disassemble the chassis: a. Set the assembly so its bottom

Removal and Installation ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual6–55H A10 Acquisition Board (page 6–39)d. Reinstall external modul

IntroductionxxTDS 684A, TDS 744A, & TDS 784A Service ManualOption 9C. When you order the TDS 684A and 7XXA Digitizing Oscilloscopeswith option 9C,

Removal and Installation Procedures6–56TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual6–57TroubleshootingThis subsection contains information and procedures designed to help you isolatefa

Troubleshooting6–58TDS 684A, TDS 744A, & TDS 784A Service Manual Firmware UpdatesDigitizing Oscilloscopes firmware updates are easy to do. Simply

TroubleshootingTDS 684A, TDS 744A, & TDS 784A Service Manual6–59Replace the A10Acquisition modulePerform the A16 Low VoltagePower Supply Module Is

Troubleshooting6–60TDS 684A, TDS 744A, & TDS 784A Service ManualReplace the A17Main LV PowerSupply module.Replace the A11 DRAMProcessor/Displaymod

TroubleshootingTDS 684A, TDS 744A, & TDS 784A Service Manual6–61Done.NoYesDoes thedisplay reportany errors?Are anyfailuresreported?The oscilloscop

Troubleshooting6–62TDS 684A, TDS 744A, & TDS 784A Service ManualThe oscilloscope may havepowered off because itover-heated. Wait 5 minutes andpowe

TroubleshootingTDS 684A, TDS 744A, & TDS 784A Service Manual6–63Table 6–5: Normal Supply Voltages (Measured on J26 and J27 on the A11 DRAMProcesso

Troubleshooting6–64TDS 684A, TDS 744A, & TDS 784A Service ManualNoYesReplace the A11 DRAMProcessor/Display module.Isthe displaylegible but the hor

TroubleshootingTDS 684A, TDS 744A, & TDS 784A Service Manual6–65 J18 pin 1 (Horizontal Sync)J18 pin 2 (Vertical Sync)Figure 6–31: Horizontal and V

IntroductionTDS 684A, TDS 744A, & TDS 784A Service ManualxxiBefore You BeginThis manual is for servicing the TDS 684A and 7XXA Digitizing Oscillos

Troubleshooting6–66TDS 684A, TDS 744A, & TDS 784A Service ManualReplace the A11 DRAMProcessor/Display module. Select the extended diagnosticsmenu

TroubleshootingTDS 684A, TDS 744A, & TDS 784A Service Manual6–67This procedure helps you determine ifthe A11 DRAM Processor/Display orthe A12 Fron

Troubleshooting6–68TDS 684A, TDS 744A, & TDS 784A Service ManualDo allthe channelsdisplay defectivewaveforms?Attach a probe to the PROBE COMPENSAT

TroubleshootingTDS 684A, TDS 744A, & TDS 784A Service Manual6–69CAUTION. Only probe points specified in the procedures. You can causecatastrophic

Troubleshooting6–70TDS 684A, TDS 744A, & TDS 784A Service ManualPin 100Pin 4J28Pin 1Pin 3Pin 5Pin 3Pin 17J27J26U1331U1097S1002U2000U2001J2J30Figur

TroubleshootingTDS 684A, TDS 744A, & TDS 784A Service Manual6–71J20U174J35Figure 6–37: A11 DRAM Processor/Display Module (View of Upper Left Corne

Troubleshooting6–72TDS 684A, TDS 744A, & TDS 784A Service ManualPin 11Pin 5 Pin 7 Pin 9U604U1001U1540Figure 6–39: A10 Acquisition Module (View of

TDS 684A, TDS 744A, & TDS 784A Service Manual7–1Options and AccessoriesThis section describes the various options as well as the standard and opti

Options and Accessories7–2TDS 684A, TDS 744A, & TDS 784A Service ManualTable 7–1: Options (Cont.)DescriptionLabelOption #1M(TDS 7XXA)130,000 recor

IntroductionxxiiTDS 684A, TDS 744A, & TDS 784A Service Manual

Options and AccessoriesTDS 684A, TDS 744A, & TDS 784A Service Manual7–3Table 7–1: Options (Cont.)DescriptionLabelOption #95 Calibration Data Repor

Options and Accessories7–4TDS 684A, TDS 744A, & TDS 784A Service ManualOptional AccessoriesYou can also order the optional accessories listed in T

Options and AccessoriesTDS 684A, TDS 744A, & TDS 784A Service Manual7–5H AM 503S — DC/AC Current probe system, AC/DC. Uses A6302 CurrentProbe.H AM

Options and Accessories7–6TDS 684A, TDS 744A, & TDS 784A Service ManualH CALXXXX provides one year of calibration support. It is available in oney

TDS 684A, TDS 744A, & TDS 784A Service Manual8–1Electrical Parts ListThe modules that make up this instrument are often a combination of mechanica

Electrical Parts List8–2TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual9–1DiagramsThis contains the block diagram and the interconnection diagram for theTDS 684A and 7XXA D

Diagrams9–2TDS 684A, TDS 744A, & TDS 784A Service ManualFlexA12FrontPanelBoardA10AcquisitionBoardFront PanelKnobsCH 1CH 2CH 3CH 4MenuSwitchesA18Ma

DiagramsTDS 684A, TDS 744A, & TDS 784A Service Manual9–3V1000A30DisplayDriverBoard2A32VideoBoardA31ShutterDriverBoard6A23SerparBoard SIGNALOUTPUTA

Diagrams9–4TDS 684A, TDS 744A, & TDS 784A Service ManualA14D1 BusFloppyDriver100A12Front PanelA10AcquisitionCH 1CH 2CH 3CH 4MenuSwitchesA18Main Co

DiagramsTDS 684A, TDS 744A, & TDS 784A Service Manual9–5V1000A30DisplayDriverA32VideoA31ShutterDriver6A23Serpar SIGNALOUTPUTAUXTRIGGERINPUTMAINTRI

Diagrams9–6TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual10–1Mechanical Parts ListThis section contains a list of the replaceable modules for the oscilloscope

Mechanical Parts List10–2TDS 684A, TDS 744A, & TDS 784A Service ManualUsing the Replaceable Parts ListThis section contains a list of the mechanic

Mechanical Parts ListTDS 684A, TDS 744A, & TDS 784A Service Manual10–3Manufacturers Cross Index Mfr.CodeManufacturer Address City, State, Zip Code

Mechanical Parts List10–4TDS 684A, TDS 744A, & TDS 784A Service ManualManufacturers Cross Index (Cont.)Mfr.CodeCity, State, Zip CodeAddressManufac

Mechanical Parts ListTDS 684A, TDS 744A, & TDS 784A Service Manual10–5This page intentionally left blank.

TDS 684A, TDS 744A, & TDS 784A Service Manual1–1SpecificationsThis section begins with a general description of the traits of the TDS 684A and7XXA

Mechanical Parts List10–6TDS 684A, TDS 744A, & TDS 784A Service ManualReplaceable Parts List Fig. &IndexNumberTektronix PartNumberSerial No.Ef

Mechanical Parts ListTDS 684A, TDS 744A, & TDS 784A Service Manual10–7A12123456789101112131314151617181920212223Figure 10–1: External Modules

Mechanical Parts List10–8TDS 684A, TDS 744A, & TDS 784A Service ManualReplaceable Parts List Fig. &IndexNumberTektronix PartNumberSerial No.Ef

Mechanical Parts ListTDS 684A, TDS 744A, & TDS 784A Service Manual10–9A14A11A10123456789101110121314151617181912Figure 10–2: Outer-Chassis Module

Mechanical Parts List10–10TDS 684A, TDS 744A, & TDS 784A Service ManualReplaceable Parts List Fig. &IndexNumberTektronix PartNumberSerial No.E

Mechanical Parts ListTDS 684A, TDS 744A, & TDS 784A Service Manual10–11Replaceable Parts List Fig. &IndexNumberTektronix PartNumberSerial No.E

Mechanical Parts List10–12TDS 684A, TDS 744A, & TDS 784A Service ManualReplaceable Parts List Fig. &IndexNumberTektronix PartNumberSerial No.E

Mechanical Parts ListTDS 684A, TDS 744A, & TDS 784A Service Manual10–1312345 67Figure 10–5: Cables, Top View

Mechanical Parts List10–14TDS 684A, TDS 744A, & TDS 784A Service ManualReplaceable Parts List Fig. &IndexNumberTektronix PartNumberSerial No.E

Mechanical Parts ListTDS 684A, TDS 744A, & TDS 784A Service Manual10–15123456Figure 10–6: Floppy Disk

Specifications1–2TDS 684A, TDS 744A, & TDS 784A Service ManualUser InterfaceUse a combination of front-panel buttons, knobs, and on-screen menus t

Mechanical Parts List10–16TDS 684A, TDS 744A, & TDS 784A Service ManualReplaceable Parts List Fig. &IndexNumberTektronix PartNumberSerial No.E

Mechanical Parts ListTDS 684A, TDS 744A, & TDS 784A Service Manual10–17Replaceable Parts List Fig. &IndexNumberTektronix PartNumberSerial No.E

Mechanical Parts List10–18TDS 684A, TDS 744A, & TDS 784A Service Manual

WARRANTYTektronix warrants that this product will be free from defects in materials and workmanship for a period of three (3) yearsfrom the date of sh

SpecificationsTDS 684A, TDS 744A, & TDS 784A Service Manual1–3Besides these channels, up to three math waveforms and four reference wave-forms are

Specifications1–4TDS 684A, TDS 744A, & TDS 784A Service ManualThe delayed display (or the intensified zone) may also be delayed by a selectednumbe

SpecificationsTDS 684A, TDS 744A, & TDS 784A Service Manual1–5H Select the mode for interpolation (linear or sin (x)/x). This can increase theappa

Specifications1–6TDS 684A, TDS 744A, & TDS 784A Service Manualwith respect to the trigger point (event) of the acquisition. The cursors can alsoco

SpecificationsTDS 684A, TDS 744A, & TDS 784A Service Manual1–7The oscilloscope can also output copies of its display using the hardcopy feature.Th

Specifications1–8TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual1–9Nominal TraitsThis section contains a collection of tables that list the various nominal traitstha

Nominal Traits1–10TDS 684A, TDS 744A, & TDS 784A Service ManualTable 1–4: Nominal Traits — Time Base System Name DescriptionRange, Sample-Rate1,3T

Nominal TraitsTDS 684A, TDS 744A, & TDS 784A Service Manual1–11Table 1–5: Nominal Traits — Triggering System (Cont.)Name DescriptionRanges, Setup

Nominal Traits1–12TDS 684A, TDS 744A, & TDS 784A Service ManualTable 1–7: Nominal Traits — GPIB Interface, Output Ports, and Power Fuse Name Descr

Nominal TraitsTDS 684A, TDS 744A, & TDS 784A Service Manual1–13Table 1–9: Nominal Traits — Mechanical Name DescriptionCooling Method Forced-air ci

Nominal Traits1–14TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual1–15Warranted CharacteristicsThis section lists the various warranted characteristics that describe t

Warranted Characteristics1–16TDS 684A, TDS 744A, & TDS 784A Service ManualTable 1–10: Warranted Characteristics — Signal Acquisition System Name D

Warranted CharacteristicsTDS 684A, TDS 744A, & TDS 784A Service Manual1–17Table 1–10: Warranted Characteristics — Signal Acquisition System (Cont.

Warranted Characteristics1–18TDS 684A, TDS 744A, & TDS 784A Service ManualTable 1–12: Warranted Characteristics — Triggering System Name Descripti

Warranted CharacteristicsTDS 684A, TDS 744A, & TDS 784A Service Manual1–19Table 1–13: Warranted Characteristics — Output Ports, Probe Compensator,

Warranted Characteristics1–20TDS 684A, TDS 744A, & TDS 784A Service ManualTable 1–14: Warranted Characteristics — Environmental (Cont.)Name Descri

TDS 684A, TDS 744A, & TDS 784A Service Manual1–21Typical CharacteristicsThis subsection contains tables that list the various typical characterist

Typical Characteristics1–22TDS 684A, TDS 744A, & TDS 784A Service ManualTable 1–15: Typical Characteristics — Signal Acquisition System (Cont.)Nam

TDS 684A, TDS 744A, & TDS 784A Service ManualiTable of ContentsGeneral Safety Summary ix. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Typical CharacteristicsTDS 684A, TDS 744A, & TDS 784A Service Manual1–23Table 1–16: Typical Characteristics — Triggering System Name DescriptionAc

Typical Characteristics1–24TDS 684A, TDS 744A, & TDS 784A Service ManualTable 1–16: Typical Characteristics — Triggering System (Cont.)Name Descri

Typical CharacteristicsTDS 684A, TDS 744A, & TDS 784A Service Manual1–25Table 1–16: Typical Characteristics — Triggering System (Cont.)Name Descri

Typical Characteristics1–26TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual2–1InstallationSupplying Operating PowerNOTE. Read all information and heed all warnings in this subs

Installation2–2TDS 684A, TDS 744A, & TDS 784A Service ManualTable 2–1: Power-Cord Conductor Identification Conductor Color Alternate ColorUnground

InstallationTDS 684A, TDS 744A, & TDS 784A Service Manual2–3Memory modules with on-board batteries allow the TDS 684A and 7XXA Digi-tizing Oscillo

Installation2–4TDS 684A, TDS 744A, & TDS 784A Service Manualcontinue. See Section 6, Maintenance, for information on diagnostics and faultisolatio

InstallationTDS 684A, TDS 744A, & TDS 784A Service Manual2–5Seal the shipping carton with an industrial stapler or strapping tape.Mark the address

Table of ContentsiiTDS 684A, TDS 744A, & TDS 784A Service ManualPerformance Tests 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Installation2–6TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual2–7Operating InstructionsBefore doing service, read the following operating instructions. These instr

Operating Instructions2–8TDS 684A, TDS 744A, & TDS 784A Service ManualBrief statusinformationPosition of waveformrecord relative tothe screen and

Operating InstructionsTDS 684A, TDS 744A, & TDS 784A Service Manual2–9Most functions can be set either by using one (or two) front-panel button(s)

Operating Instructions2–10TDS 684A, TDS 744A, & TDS 784A Service Manual2. Select the waveform source(s). Position, scale, and set trigger level fo

Operating InstructionsTDS 684A, TDS 744A, & TDS 784A Service Manual2–11e. Adjust trigger level (6) to trigger the waveform(s) selected or use thes

Operating Instructions2–12TDS 684A, TDS 744A, & TDS 784A Service Manuale. Select the setting for the function from the side menu (9) using theside

Operating InstructionsTDS 684A, TDS 744A, & TDS 784A Service Manual2–132. Set up a function using the general purpose knob (20). (The examples ofp

Operating Instructions2–14TDS 684A, TDS 744A, & TDS 784A Service ManualH Gated measurementsH Number of eventsH Template generationH Trigger positi

Operating InstructionsTDS 684A, TDS 744A, & TDS 784A Service Manual2–15Display and Utility Menus. Using the techniques described for using menus,

Table of ContentsTDS 684A, TDS 744A, & TDS 784A Service ManualiiiList of FiguresFigure 2–1: Map of Display Functions 2–8. . . . . . . . . . . . .

Operating Instructions2–16TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual3–1Theory of OperationThis section describes the electrical operation of the TDS 684A and 7XXA Digi-t

Theory of Operation3–2TDS 684A, TDS 744A, & TDS 784A Service Manualselected and the input is overloaded, the processor system switches the input t

Theory of OperationTDS 684A, TDS 744A, & TDS 784A Service Manual3–3The processor system sends instructions to and receives information from theFro

Theory of Operation3–4TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual4–1Performance Verification ProceduresTwo types of Performance Verification procedures can be perform

Performance Verification Procedures4–2TDS 684A, TDS 744A, & TDS 784A Service ManualConventionsThroughout these procedures the following convention

Performance Verification ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual4–3the five buttons to the right of the display. “Pop-up menu” ref

Table of ContentsivTDS 684A, TDS 744A, & TDS 784A Service ManualFigure 4–31: 60 Hz Rejection Test Setup Signal 4–72. . . . . . . . . . . . . . . .

Performance Verification Procedures4–4TDS 684A, TDS 744A, & TDS 784A Service Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual4–5Brief ProceduresThe Self Tests use internal routines to confirm basic functionality and properadju

Brief Procedures4–6TDS 684A, TDS 744A, & TDS 784A Service Manuale. Confirm the three adjustment sections have passed status:H Press SHIFT; then pr

Brief ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual4–72. Return to regular service: Press CLEAR MENU to exit the system menus.Functional

Brief Procedures4–8TDS 684A, TDS 744A, & TDS 784A Service ManualEquipmentRequiredOne probe such as the P6245 or P6139APrerequisites None1. Install

Brief ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual4–92. Verify that all channels operate: Do the following substeps — test CH 1first, s

Brief Procedures4–10TDS 684A, TDS 744A, & TDS 784A Service ManualH Sample mode displays an actively acquiring waveform on-screen.(Note that there

Brief ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual4–11a. One period of the square-wave probe-compensation signal is about fivehorizonta

Brief Procedures4–12TDS 684A, TDS 744A, & TDS 784A Service Manual2. Verify that the main trigger system operates: Confirm that the followingstatem

Brief ProceduresTDS 684A, TDS 744A, & TDS 784A Service Manual4–13H Verify that the trigger READY indicator on the front panel flashesabout once ev

Table of ContentsTDS 684A, TDS 744A, & TDS 784A Service ManualvFigure 6–16: A11 Processor/Display Removal 6–37. . . . . . . . . . . . . . . . . .

Brief Procedures4–14TDS 684A, TDS 744A, & TDS 784A Service Manuale. Save the settings:H Press SETUP.H Press the main-menu button Save Current Setu

TDS 684A, TDS 744A, & TDS 784A Service Manual4–15Performance TestsThis section contains a collection of procedures for checking that the TDS 684Aa

Performance Tests4–16TDS 684A, TDS 744A, & TDS 784A Service ManualEquipment RequiredThese procedures use external, traceable signal sources to dir

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–17Table 4–1: Test Equipment (Cont.)Item Number and DescriptionPurposeExampleMinimu

Performance Tests4–18TDS 684A, TDS 744A, & TDS 784A Service Manual

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–19TDS 684A Test RecordPhotocopy this and the next three pages and use them to reco

Performance Tests4–20TDS 684A, TDS 744A, & TDS 784A Service ManualTDS 684A Test Record (Cont.)Instrument Serial Number: Certificate Number:Tempera

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–21TDS 684A Test Record (Cont.)Instrument Serial Number: Certificate Number:Tempera

Performance Tests4–22TDS 684A, TDS 744A, & TDS 784A Service ManualTDS 684A Test Record (Cont.)Instrument Serial Number: Certificate Number:Tempera

Performance TestsTDS 684A, TDS 744A, & TDS 784A Service Manual4–23TDS 7XXA Test RecordPhotocopy this and the next three pages and use them to reco