Service Manual THS710A, THS720A, THS730A & THS720P TekScope 070-9752-01 This document applies to to serial number B010100 and above and firmware version 1.00 and above. First printing: February 1998 Warning The servicing instructions are for use by qualified personnel only. To avoid personal injury, do not perform any servicing unless you are qualified to do so. Refer to all safety summaries prior to performing service.
Copyright E Tektronix, Inc. 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. Tek Secure is a registered trademark 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 purchase from an authorized Tektronix distributor. 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. Batteries are excluded from this warranty.
Service Assurance If you have not already purchased Service Assurance for this product, you may do so at any time during the product’s warranty period. Service Assurance provides Repair Protection and Calibration Services to meet your needs. Repair Protection extends priority repair services beyond the product’s warranty period; you may purchase up to three years of Repair Protection.
Table of Contents General Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v vii ix Related Manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents Options Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–1 Electrical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8–1 Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9–1 Parts Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using the Replaceable Parts List . .
Table of Contents List of Figures Figure 2–1: Removing and replacing the battery . . . . . . . . . . . . . . . . . Figure 2–2: AC adapter attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2–3: Typical scope-mode display . . . . . . . . . . . . . . . . . . . . . . . . Figure 2–4: Typical meter-mode display . . . . . . . . . . . . . . . . . . . . . . . . Figure 2–5: Connector locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents List of Tables iv Table 1–1: Oscilloscope specifications . . . . . . . . . . . . . . . . . . . . . . . . . Table 1–2: DMM specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1–3: General specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–1 1–8 1–10 Table 5–1: Summary of oscilloscope adjustment steps . . . . . . . . . . . . Table 5–2: Summary of meter adjustment steps . . . . . . . . . . . . . . . . .
General Safety Summary Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it. To avoid potential hazards, use this product only as specified. Only qualified personnel should perform service procedures. To Avoid Fire or Personal Injury Connect and Disconnect Properly. Do not connect or disconnect probes or test leads while they are connected to a voltage source. Observe All Terminal Ratings.
General Safety Summary Symbols and Terms Terms in this Manual. These terms may appear in this manual: WARNING. Warning statements identify conditions or practices that could result in injury or loss of life. CAUTION. Caution statements identify conditions or practices that could result in damage to this product or other property. Terms on the Product. These terms may appear on the product: DANGER indicates an injury hazard immediately accessible as you read the marking.
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. Use Care When Servicing With Power On. Dangerous voltages or currents may exist in this product.
Service Safety Summary viii THS710A, THS720A, THS730A & THS720P Service Manual
Preface This is the Service Manual for the THS710A, THS720A, THS730A, and THS720P TekScope instruments. This manual provides information to troubleshoot and repair the instrument to the module level. Related Manuals Additional documentation for the instrument is contained in the related manuals listed below.
Preface Conventions In the Performance Verification, Adjustments, and Maintenance chapters of this manual, TekScope instrument setups are shown in tables similar to the one shown below. The header of each table contains icons that represent the controls and menu items used to set up the instrument. To make a specific setup, read the table from left to right and then from top to bottom as shown below. The table contains the symbol “—” if no action is required. 1. Choose scope mode or meter mode. x 2.
Specifications This chapter contains the oscilloscope, DMM, and general specifications for the THS710A, THS720A, THS730A, and THS720P TekScope instruments. All specifications are guaranteed unless noted “typical.” Typical specifications are provided for your convenience but are not guaranteed. Specifications that are marked with the n symbol are checked in the chapter Performance Verification. All specifications apply to all four instruments unless noted otherwise.
Specifications Table 1–1: Oscilloscope specifications (Cont.) Inputs Maximum Voltage Between Common and Earth Ground at BNC 600 VRMS (CAT II) or 300 VRMS (CAT III), using rated connectors or accessories Maximum Voltage, Channel-to-Channel Commons 30 VRMS, 42.
Specifications Table 1–1: Oscilloscope specifications (Cont.) Vertical DC Gain Accuracy ±2% for Sample or Average acquisition mode Position Accuracy ±[0.4% × |(position × volts/div)| + (0.1 div × volts/div)] n DC Measurement A r y Average Accuracy, A er e Acquisition Mode Using ≥16 Wavef rms forms Measurement Type Accuracy Absolute voltage measurements ±[2% × |reading + (position × volts/div)| + (0.
Specifications Table 1–1: Oscilloscope specifications (Cont.) Internal Trigger Trigger Sensitivity, d e Trigger Tr er Type, Type Edge typical yp Coupling Sensitivity NOISE REJ 3.5 times the DC-coupled limits HF REJ 1.5 times the DC-coupled limit from DC to 30 kHz, attenuates signals above 30 kHz LF REJ 1.5 times the DC-coupled limits for frequencies above 1 kHz, attenuates signals below 1 kHz Trigger Level Range ±4 divisions from center of screen Motor Trigger Level Range (THS720P) 0.
Specifications Table 1–1: Oscilloscope specifications (Cont.
Specifications Table 1–1: Oscilloscope specifications (Cont.) Power Measurements (THS720P) PF Measurement Power factor (PF) true power W VA apparent power q Measurement q is the phase difference between the fundamental components of voltage and current. Positive angle means voltage leads current. Negative angle means voltage lags current. DPF Measurement Displacement power factor (DPF) = cos Power Factor Measurements Accuracy ±0.
Specifications Table 1–1: Oscilloscope specifications (Cont.
Specifications Table 1–2: DMM specifications General Resolution 33⁄4 digit, 4000 count full scale reading except as noted Input Resistance, AC or DC Voltage 10 M ±10% Input Capacitance, AC or DC Voltage, typical ≤100 pF Maximum Voltage e ee DMM D Between andd COM Inputs Overvoltage Category Maximum Voltage CAT I Environment (refer to page 1–13) 640 VRMS (880 VDC) CAT II Environment (refer to page 1–13) 600 VRMS CAT III Environment (refer to page 1–13) 300 VRMS Overvoltage Category Maximum
Specifications Table 1–2: DMM specifications (Cont.) AC Voltage Conversion Type AC conversions are true RMS. The AC measurement is based on the AC and DC components of the signal as shown below: AC Measurement = RMS(AC+DC) – DC Ranges and Res Resolution n Accuracy 40 Hz to 500 Hz) (40 Common Mode Rejection, typical Range Resolution 400.0 mV 0.1 mV 4.000 V 1 mV 40.00 V 10 mV 400.
Specifications Table 1–2: DMM specifications (Cont.) /Resistance Open Circuit Voltage, yp typical Range Open Circuit Voltage 400.0 4.8 V All other ranges ≤1.
Specifications Table 1–3: General specifications (Cont.) RS-232 Interface Device Type DTE. at RJ-45 connector Pinout Signal Pin Number at Pin Number at 9-pin Null RJ-45 Modem Adapter Connector RTS out 1 8 TXD out 2 6 RXD in 3 5 GND 5 4 DTR out 6 3 CTS in 7 7 RTS out 8 8 DSR in (not used) 4 2 DCD in (not used) 7 1 Probe Compensator Output Output Voltage, typical 5.0 V into ≥1 M load Frequency, typical 1.
Specifications Table 1–3: General specifications (Cont.) Environmental Temperature Humidity Altitude Random Vibration Operating –10° C to +50° C Nonoperating –20° C to +60° C +40° C or below ≤95% relative humidity +41° C to +50° C ≤75% relative humudity Operating 2,000 m Nonoperating 15,000 m Operating 2.66 gRMS from 5 Hz to 500 Hz, 10 minutes on each axis Nonoperating 3.
Specifications Table 1–3: General specifications (Cont.) Certifications and Compliances Certifications Listed UL3111-1 and CAN/CSA-C22.2 No. 1010.1-92, complies with EN61010-1 /A2 Overvoltage Category Category Examples CAT III A typical CAT III environment is the power distribution system within a building or factory. These environments are somewhat protected from lightning strikes, but susceptible to switching transients and other disturbances that may generate high voltage impulses.
Specifications 1–14 THS710A, THS720A, THS730A & THS720P Service Manual
Operating Information This chapter provides a quick overview of the following topics: H Internal and external power sources H Understanding the front panel H Connecting and using the probes For more detailed information about TekScope instrument operation, refer to the THS710A, THS720A, THS730A, & THS720P User Manual. For information about unpacking and inspecting the instrument, refer to Unpacking and Repacking Instructions on page 6–40 of this manual.
Operator Information Battery pack Figure 2–1: Removing and replacing the battery Using External Power For benchtop operation, you can use external power. Attach the AC adapter as shown in Figure 2–2. The DC INPUT disconnects itself if an overvoltage is applied. If this occurs, disconnect and then reconnect the AC adapter to resume operation from external power. WARNING. To avoid shock hazard, the DC input and I/O port hole plugs must remain closed in wet or damp conditions.
Operator Information CAUTION. To avoid overheating, do not connect external power while the instrument is in a confined space, such as in the soft case. Understanding the Front Panel The SCOPE and METER buttons select the operating mode. The front panel has additional buttons for the functions you use most often and menus to access the more specialized functions. Using Scope Mode Press the front-panel SCOPE button to enter scope mode.
Operator Information Using Meter Mode Press the front-panel METER button to enter meter mode. Press one of the bezel buttons to choose a meter function and then press AUTORANGE to set the range automatically. A typical meter-mode display is shown in Figure 2–4.
Operator Information Using the Menu System To use the menu system, follow the steps below: 1. Press a front-panel button to display the menu you want to use. 2. Press a bezel button to choose a menu item. If a pop-up menu appears, continue to press the bezel button to choose an item in the pop-up menu. You may need to press the Select Page button to access additional menu items.
Operator Information 3. After choosing some menu items, you need to set a numerical parameter to complete the setup. Use the +/– rocker to adjust the parameter or press the TOGGLE button to reset the parameter to its default value. 4. If the OK bezel button is displayed, press it to confirm your choice. NOTE. In the Performance Verification, Adjustments, and Maintenance chapters of this manual, TekScope instrument setups are shown in tables.
Operator Information Using the Dedicated Buttons You can use the dedicated buttons below to take direct actions. These buttons do not require the use of menus. 1 3 2 4 16 15 5 14 6 13 12 11 10 9 8 7 1. HARD COPY. Initiates a hard copy using the RS-232 port. 2. HOLD. Stops/restarts oscilloscope acquisition or holds/resets meter readout. 3. AUTORANGE. Selects oscilloscope or meter autorange function. 4. CLEAR MENU. Clears menu from display. 5. TRIGGER LEVEL. Adjusts trigger level. 6.
Operator Information 14. CH 1, CH 2, MATH, REF A, REF B. Displays waveform and chooses selected waveform. In harmonics mode (THS720P), CH 1 and CH 2 also display harmonics of voltage and current waveforms; MATH displays power measurements. 15. SCOPE. Selects scope mode. 16. METER. Selects meter mode. Connecting and Using the Probes The oscillscope probes and meter leads attach to the connectors located on the top and side panels of the TekScope instrument as shown in Figure 2–5.
Operator Information Compensating the Oscilloscope Probes To maintain signal fidelity, you must compensate each voltage probe for the channel input it is connected to. 1. Connect the oscilloscope probe and then press AUTORANGE. Ch 1 Probe reference lead to Probe tip to PROBE COMP AUTORANGE 2. Check the shape of the displayed waveform. Overcompensated Undercompensated Compensated correctly 3. If necessary, adjust the probe for correct compensation. P6117 P5102 4.
Operator Information Attaching the Reference Leads Correctly If you are using both of the oscilloscope channels, you must attach the probe reference lead for each channel directly to your circuit. These attachments are required because the oscilloscope channels are electrically isolated; they do not share a common chassis connection. If you are also using the DMM, you must also attach the DMM common lead to your circuit for the same reason as above.
Theory of Operation This chapter describes the electrical operation of the TekScope instrument to the module level. It describes the basic operation of each functional circuit block shown in Figure 3–1. Main Board The Main board assembly contains the following oscilloscope and meter functions. Oscilloscope Signal Path Each of the two oscilloscope input signals enters the main board and passes through an attenuator and buffer amplifier.
Theory of Operation Display Module The display module consists of a liquid crystal display (LCD), a display driver, and a flourescent backlight. Switch Assembly The switch assembly is a matrix of switches that form the front-panel buttons. The switch assembly consists of a flex-circuit board and an elastomeric switch mat. Switch closures are read by the processor system.
Performance Verification This chapter contains performance verification procedures for the specifications marked with the n symbol. The following equipment, or a suitable equivalent, is required to complete these procedures. Description Minimum Requirements Examples DC Voltage Source 60 mV to 800 V, ±0.1% accuracy AC Voltage Source 300 mV to 640 V, ±0.5% accuracy at 500 Hz Resistance Standard 360 to 36 M , ±0.
Performance Verification Test Record Serial Number Procedure Performed by Date Test Passed Failed Test Result High Limit Self Test Oscilloscope Tests Channel 1 DC Measureme r y ment A Accuracy Low Limit 5 mV/div 34.05 mV 35.95 mV 500 mV/div 3.405 V 3.595 V 2 V/div 13.62 V 14.38 V 10 V/div 68.1 V 71.9 V 5 mV/div 34.05 mV 35.95 mV 500 mV/div 3.405 V 3.595 V 2 V/div 13.62 V 14.38 V 10 V/div 68.1 V 71.
Performance Verification DMM Tests DC Voltage Accuracy AC Voltage Accuracy Resistance Accuracy Low Limit Test Result High Limit 400 mV range, 60 mV input 59.2 mV 60.8 mV 400 mV range, 360 mV input 357.7 mV 362.3 mV 4 V range 3.577 V 3.623 V 40 V range 35.77 V 36.23 V 400 V range 357.7 V 362.3 V 880 V range 783 V 801 V 400 mV range 352.3 mV 367.7 mV 4 V range, 600 mV input 0.583 V 0.617 V 4 V range, 3.6 V input 3.523 V 3.677 V 40 V range 35.23 V 36.77 V 400 V range 352.
Performance Verification Performance Verification Procedures In these procedures, TekScope instrument setups are shown in tables. Refer to Conventions on page x for information about how to use these tables. Before beginning these procedures, two conditions must first be met: H The TekScope instrument must have been operating continuously for ten minutes within the operating temperature range specified. H You must perform the Signal Path Compensation operation described below.
Performance Verification Execute Self Test This procedure uses internal routines to verify that the TekScope instrument functions and passes its internal self tests. No test equipment or hookups are required. Start the self test with the following setup: SCOPE UTILITY System Diag Loop Once Execute — OK Run Test A dialog box displays the result when the self test completes. Press the CLEAR MENU button to continue operation.
Performance Verification Check Oscilloscope DC Measurement Accuracy This test checks the DC measurement accuracy of the oscilloscope. 1. Set the DC voltage source output level to 0 V. 2.
Performance Verification 4. For each VOLTS/DIV setting listed below, perform the following steps: a. Set the DC voltage source output level to the positive voltage listed and then record the mean measurement as Vpos. b. Reverse the polarity of the DC voltage source and then record the mean measurement as Vneg. c. Calculate Vdiff = Vpos – Vneg and then compare Vdiff to the accuracy limits in the table. VOLTS/DIV Setting DC Voltage Source Output Levels Accuracy Limits for Vdiff 5 mV/div +17.5 mV, –17.
Performance Verification Check Oscilloscope Channel 1 Bandwidth This test checks the bandwidth of channel 1. 1. Set up the TekScope instrument using the following steps: SCOPE * Recall Saved Setup Recall Factory Setup OK Recall Factory — ACQUIRE Mode Average Set to 16 TRIGGER Coupling Noise Reject — MEAS Gating & High-Low Setup High-Low Method Min/Max Select Measrmnt Pk-Pk* — OK Select Measrmnt — SAVE/ RECALL — You may need to press Select Page to display this selection. 2.
Performance Verification 3. Set the TekScope instrument VOLTS/DIV to 100 mV/div. 4. Set the TekScope instrument SEC/DIV to 10 s/div. 5. Set the leveled sine wave generator frequency to 50 kHz. 6. Set the leveled sine wave generator output level so the peak-to-peak measurement is between 599 mV and 601 mV. 7. Set the leveled sine wave generator frequency to 200 MHz if you are checking a THS730A, 100 MHz if you are checking a THS720A or a THS720P, or 60 MHz if you are checking a THS710A. 8. Press MAG. 9.
Performance Verification Check Oscilloscope Channel 2 Bandwidth This test checks the bandwidth of channel 2. 1. First check the channel 1 bandwidth using the previous test. Then, perform these additional steps to check the channel 2 bandwidth: SCOPE CH 1 — — — TRIGGER Trigger Source Ch2 MEAS Gating & High-Low Setup High-Low Method Min/Max Select Measrmnt Pk-Pk* — OK Select Measrmnt — WAVEFORM OFF CH 2 * You may need to press Select Page to display this selection. 2.
Performance Verification 3. Set the TekScope instrument VOLTS/DIV to 100 mV/div. 4. Set the TekScope instrument SEC/DIV to 10 s/div. 5. Set the leveled sine wave generator frequency to 50 kHz. 6. Set the leveled sine wave generator output level so the peak-to-peak measurement is between 599 mV and 601 mV. 7. Set the leveled sine wave generator frequency to 200 MHz if you are checking a THS730A, 100 MHz if you are checking a THS720A or a THS720P, or 60 MHz if you are checking a THS710A. 8. Press MAG. 9.
Performance Verification Check Oscilloscope Sample Rate and Delay Time Accuracy This test checks the oscilloscope time base accuracy. 1. Set up the TekScope instrument using the following steps: SCOPE SAVE/ RECALL VERTICAL MENU Recall Saved Setup Recall Factory Setup OK Recall Factory — Probe Type Voltage Probe — Set to 1X 2. Connect the TekScope instrument to the time mark generator as shown below. 50 feedthrough terminator Time mark generator Ch 1 Output BNC cable 3.
Performance Verification 6. Press SET LEVEL TO 50%. 7. Press MAG. 8. Change the TekScope instrument setup using the following steps: SCOPE HORIZONTAL MENU Time Base Delayed Runs After — Main CLEAR MENU — — 9. Set the delayed time base SEC/DIV to 50 ms/div. 10. Change the TekScope instrument setup using the following steps: SCOPE HORIZONTAL MENU Time Base Delayed Runs After Set delay time to Main 10 ms CLEAR MENU — — — 11. Set the delayed time base SEC/DIV to 500 ns/div. 12.
Performance Verification Check Oscilloscope Channel 1 Edge Trigger Sensitivity This test checks the edge trigger sensitivity for channel 1. 1.
Performance Verification 3. Set the leveled sine wave generator frequency to 200 MHz if you are checking a THS730A or to 100 MHz if you are checking a THS710A, THS720A or THS720P. 4. Set the TekScope instrument VOLTS/DIV to 500 mV/div. 5. Press MAG. 6. Set the TekScope instrument SEC/DIV to 10 ns/div. 7. Set the leveled sine wave generator output level to approximately 50 mVp-p so that the measured amplitude is approximately 500 mV. (The measured amplitude can fluctuate around 500 mV.) 8.
Performance Verification Check Oscilloscope Channel 2 Edge Trigger Sensitivity This test checks the edge trigger sensitivity for channel 2. 1. First check the channel 1 edge trigger sensitivity using the previous test.
Performance Verification 3. Set the leveled sine wave generator frequency to 200 MHz if you are checking a THS730A or to 100 MHz if you are checking a THS710A, THS720A or THS720P. 4. Set the TekScope instrument VOLTS/DIV to 500 mV/div. 5. Set the leveled sine wave generator output level to approximately 50 mVp-p so that the measured amplitude is approximately 500 mV. (The measured amplitude can fluctuate around 500 mV.) 6. Press SET LEVEL TO 50%.
Performance Verification Check Meter DC Voltage Accuracy This test checks the meter DC voltage accuracy. 1. Set the DC voltage source output level to 0 V. 2. Set up the TekScope instrument using the following steps: METER — VDC — 3. Connect the TekScope instrument to the DC voltage source as shown below.
Performance Verification 4. For each range, set the DC voltage source output to the level listed below, and then compare the meter reading to the accuracy limits. Range DC Voltage Source Output Level Accuracy Limits 400 mV 60 mV 59.2 mV to 60.8 mV 400 mV 360 mV 357.7 mV to 362.3 mV 4V 3.6 V 3.577 V to 3.623 V 40 V 36 V 35.77 V to 36.23 V 400 V 360 V 357.7 V to 362.3 V 880 V 792 V 783 V to 801 V 5. Set the DC voltage source output level to 0 V.
Performance Verification Check Meter AC Voltage Accuracy This test checks the meter AC voltage accuracy. 1. Set the AC voltage source output level to 0 V. 2. Set up the TekScope instrument using the following steps: METER — VAC — 3. Connect the TekScope instrument to the AC voltage source as shown below.
Performance Verification 4. Set the AC voltage source output frequency to 500 Hz. 5. For each range, set the AC voltage source output to the level listed below, and then compare the meter reading to the accuracy limits. Range AC Voltage Source Output Level Accuracy Limits 400 mV 360 mV 352.3 mV to 367.7 mV 4V 600 mV 0.583 V to 0.617 V 4V 3.6 V 3.523 V to 3.677 V 40 V 36 V 35.23 V to 36.77 V 400 V 360 V 352.3 V to 367.7 V 640 V 576 V 559 V to 593 V 6.
Performance Verification Check Meter Resistance Accuracy This test checks the meter resistance measurement accuracy. 1. Set up the TekScope instrument using the following steps: METER — — 2. Connect the TekScope instrument to the resistance standard as shown below.
Performance Verification 3. For each range, set the resistance standard to the resistance listed below, and then compare the meter reading to the accuracy limits. Range Resistance Standard Setting Accuracy Limits 400 360 358.0 to 362.0 4 k 3.6 k 3.580 k to 3.620 k 40 k 6 k 5.95 k to 6.05 k 40 k 36 k 35.80 k to 36.20 k 400 k 360 k 358.0 k to 362.0 k 4 M 3.6 M 3.580 M to 3.620 M 40 M * 36 M * 35.23 M to 36.
Performance Verification 4–24 THS710A, THS720A, THS730A & THS720P Service Manual
Adjustment Procedures This chapter contains adjustment procedures for the TekScope instrument. Only qualified personnel should perform service procedures. Read this Service Safety Summary and the General Safety Summary before performing any service procedures. Also refer to the chapter Operating Information for information about using the TekScope instrument. NOTE. The voltage references inside the TekScope instrument are very stable over time and should not require routine adjustment.
Adjustment Procedures Description Minimum Requirements Dual Banana to BNC Adapter Banana plugs to BNC female Tektronix part number 103-0090-XX BNC T One male and two female BNC connectors Tektronix part number 103-0030-XX Examples Overview of the Adjustment Process The TekScope instrument is protected from inadvertent adjustment by an internal adjustment-lockout jumper. Some disassembly is required to access and remove the jumper before you can adjust the instrument.
Adjustment Procedures Accessing the Adjustment-Lockout Jumper Before adjusting the instrument you must (temporarily) remove the internal adjustment-lockout jumper. You will need a 12 in ⋅ lb (1.3 N ⋅ m) torque-limiting screwdriver with Torx T-15 tip and a pair of needle-nose pliers to access and remove the jumper. WARNING. Before doing this or any other procedure in this manual, read the General Safety Summary and Service Safety Summary found at the beginning of this manual.
Adjustment Procedures Adjustment-lockout jumper Figure 5–1: Location of adjustment-lockout jumper 11. To install the switch mat, place it (contact side down) on the switch flex-circuit assembly. The five rubber guideposts fit into holes in the circuit board. 12. Place the front cover assembly onto the instrument. Taking care not to pinch the handle, align it into the guides in the front cover. Align the buttons so they all protrude through the holes in the front cover. 13.
Adjustment Procedures c. When all four all screws are in, hold a corner of the case together firmly to compress the gasket while tightening its screw until snug. Repeat for the other corners. Do not overtighten the screws (14 in ⋅ lbs or 1.5 N ⋅ m maximum torque). 15. Replace the battery as shown on page 2–2, and then close the battery door. Oscilloscope Adjustment Three equipment setups, shown in Figure 5–2, are required to complete this adjustment procedure.
Adjustment Procedures Square wave generator setup 10 inch BNC cable BNC ‘T’ connector Fast rise square wave generator 50 feedthrough terminator Ch 1 Ch 2 Output 36 inch BNC cable Zero voltage setup 10 inch BNC cable BNC ‘T’ connector 50 feedthrough terminator Ch 1 Ch 2 DC voltage setup 10 inch BNC cable DC voltage source BNC ‘T’ connector Ch 1 Ch 2 – + Dual banana to bnc adapter 36 inch BNC cable Figure 5–2: Oscilloscope adjustment setups 5–6 THS710A, THS720A, THS730A & THS720P Se
Adjustment Procedures Oscilloscope Adjustment Procedure After removing the adjustment-lockout jumper, use this procedure to adjust the oscilloscope voltage references. 1. Turn on the TekScope instrument and let it warm up for at least ten minutes. 2. Connect the fast rise square wave generator to the instrument as shown in the Square wave generator setup of Figure 5–2. 3.
Adjustment Procedures Meter Adjustment Three equipment setups, shown in Figure 5–3, are required to complete this adjustment procedure. For each step in the procedure, the specific input signal required by that step is described in the TekScope instrument display. Refer to these diagrams as necessary during the procedure. Table 5–2 summarizes the steps in the procedure and the signal requirement for each step.
Adjustment Procedures DC voltage setup DC voltage source – + Banana cables AC voltage setup AC voltage source Banana cables Resistance standard setup Resistance standard Banana cables Figure 5–3: Meter adjustment setups THS710A, THS720A, THS730A & THS720P Service Manual 5–9
Adjustment Procedures Meter Adjustment Procedure After removing the adjustment-lockout jumper, use this procedure to adjust the meter voltage references. 1. Turn on the TekScope instrument and let it warm up for at least ten minutes. 2. Connect the DC voltage source to the instrument as shown in the DC voltage setup of Figure 5–3. 3. Set the DC voltage source amplitude to 400 mV. 4. Use the TekScope instrument setup below to start the meter adjustment process.
Adjustment Procedures Replacing the Adjustment-Lockout Jumper After you complete the adjustment process, you should reinstall the adjustmentlockout jumper to prevent inadvertent loss of calibrration. To replace the jumper, repeat the procedure Accessing the Adjustment-Lockout Jumper on page 5–3. However, in place of step 9, reinstall the jumper onto pins 1 and 2 as shown in Figure 5–4.
Adjustment Procedures 5–12 THS710A, THS720A, THS730A & THS720P Service Manual
Maintenance This chapter contains the information needed to do periodic and corrective maintenance on the TekScope instrument. The following sections are included: H Preparation refers you to important information contained elsewhere in this manual. H Preventing ESD provides general information on preventing damage to internal modules when doing maintenance. H Inspection and Cleaning provides procedures for inspecting the TekScope instrument and cleaning its external and internal modules.
Maintenance 3. Discharge the static voltage from your body by wearing a grounded antistatic wrist strap while handling these modules. Do service of static-sensitive modules only at a static-free work station. 4. Nothing capable of generating or holding a static charge should be allowed on the work station surface. 5. Handle circuit boards by the edges when possible. 6. Do not slide the modules over any surface. 7.
Maintenance Inspection — Exterior. Inspect the outside of the TekScope instrument for damage, wear, and missing parts. Instruments that appear to have been dropped or otherwise abused should be checked thoroughly to verify correct operation and performance. Immediately repair defects that could cause personal injury or lead to further damage to the instrument. Cleaning Procedure — Exterior. To clean the TekScope instrument exterior, perform the following steps: 1.
Maintenance Table 6–1: Internal inspection check list (Cont.) Item Inspect For Repair Action Solder connections Cold solder or rosin joints. Resolder joint and clean with isopropyl alcohol. Wiring and cables Loose plugs or connectors. Burned, broken, or frayed wiring. Firmly seat connectors. Repair or replace modules with defective wires or cables. Cleaning Procedure — Interior. To clean the TekScope instrument interior, perform the following steps: 1.
Maintenance Removal and Installation Procedures This section describes how to remove and install the major mechanical and electrical modules. It provides the following information: Preparation H List of Modules on page 6–5 describes where to locate a list of replaceable modules. H Summary of Procedures on page 6–6 lists the procedures for removal and installation of modules. H Tools Required on page 6–7 describes the tools needed to perform the procedures.
Maintenance Summary of Procedures Table 6–2 lists the removal and installation procedures in order of increasing complexity.
Maintenance Tools Required You will need the following tools to remove and replace all the modules in the TekScope instrument. H Torque-limiting screwdriver, 12 in ⋅ lb (1.
Maintenance Tilt Stand You will need a 1@4 inch flat-bladed screwdriver to remove the tilt stand. STOP. You do not have to remove the tilt stand to access internal modules. In most cases, you do not have to remove the tilt stand to clean the TekScope instrument exterior. Removal. Use this procedure to remove a defective tilt stand. 1. Place the TekScope instrument face down on a soft surface (such as an anti-static mat). 2.
Maintenance Installation. Use this procedure to install a new tilt stand. 1. Orient the tilt stand to the back of the instrument case with the hinge pins toward the top and the side bump toward the handle. 2. Insert one hinge pin into its socket and place the other into the cavity in the back of the instrument case as shown in Figure 6–2. 3. Rotate the tilt stand to slide the second hinge pin upward and into its socket. 1 Insert hinge pin into the socket.
Maintenance Front-Panel Label You will need a sharp knife and needle-nose pliers to remove a defective front-panel label. CAUTION. Removal of a front-panel label will destroy it. Do not remove it unless it is defective and needs to be replaced. Removal. Use this procedure to remove a defective front-panel label. 1. Use the sharp knife to pry up a corner of the label. 2. Use the needle-nose pliers to peel the label off. Installation.
Maintenance Front Cover You will need a torque-limiting Torx T-15 screwdriver, needle-nose pliers, and sharp knife to remove the front cover and other immediately accessible modules. CAUTION. Attempting to remove the display shield from the front cover will likely destroy both pieces. If one or the other are defective, both must be replaced. Removal. Use this procedure to remove the front cover and access the handle, switch mat, battery door, and gasket. 1.
Maintenance Figure 6–4: Removing the battery door NOTE. In most cases, the gasket does not have to be removed from the front cover for interior cleaning. 10. To remove the gasket from the front cover, use the needle-nose priers to lift it out of the groove in the front cover, starting with the accessible tail at the bottom of the front cover. Installation. Use this procedure to install the battery door, switch mat, handle, gasket, and front cover. 1.
Maintenance 4. If you are installing a new front cover, follow these steps to assemble it before installation. Refer to Figure 6–5. a. Install a new label using the procedure on page 6–10. b. Install a new display shield into the inside of the new front cover. Remove the backing paper from the adhesive on the display shield, align it over the two diagonal posts, and then press it into place. The blue border should be even when viewed from the face of the front cover. c.
Maintenance Gasket material Front cover Trim tails to 1@8 inch Overlap gasket material Figure 6–6: Installing the gasket 5. Slip the handle into the guides of the back cover as shown in Figure 6–7. 6. Place the front cover assembly onto the instrument. Taking care not to pinch the handle, align it into the guides in the front cover. Align the buttons so they all protrude through the holes in the front cover. 7. Holding the case together, pick it up and place it front side down on a soft surface.
Maintenance Velcro strip Fold end of handle over Figure 6–7: Installing the handle THS710A, THS720A, THS730A & THS720P Service Manual 6–15
Maintenance CAUTION. To avoid cross-threading or cutting new threads with the screws, carefully follow the procedure in the next step. 8. To install the four screws, follow these steps: a. Place the screws into their holes in the back cover. b. Using the torque-limiting Torx T-15 screwdriver, slowly turn each screw backward (counterclockwise) until you feel the thread drop and then gently tighten the screw (turn clockwise) into the existing thread. c.
Maintenance Display module Display cable connector Inverter board Spring Switch flex-circuit board Figure 6–8: Removing the display module c. Using the 1@8 inch flat-bladed screwdriver, carefully open the displaycable connector as shown in Figure 6–9. d. When the connector is open, slip the display cable out of the connector to free the display module.
Maintenance Contact side of cable Figure 6–9: Opening the display cable connector Installation. Use this procedure to install the display module and inverter board. 1. Open the display-cable connector on the back of the display module. 2. Hold the display module upright as shown in Figure 6–8. 3. Insert the display cable into its connector and then use the 1@8 inch flat-bladed screwdriver to close the connector. Check that the display cable is fully inserted into the connector. 4.
Maintenance Display module Inverter output connector Route cable through channels Inverter board Inverter input connector Route cable through channel Route cable under clip Figure 6–10: Routing cables to the inverter board Back Cover You will need a 18@ inch flat-bladed screwdriver and needle-nose pliers to remove the chassis assembly and hole plugs from the back cover. NOTE. The back labels and battery contacts are an integral part of the back cover.
Maintenance 4. Carefully lift the bottom of the chassis out of the back cover. As the chassis assembly comes out, pull it toward you to back the BNC connectors out of their holes in the back cover. Figure 6–11: Lifting the chassis 5. When the chassis is free from the back cover, set it aside with the main board facing down on a soft, static-free surface. 6. To remove a defective DC power hole plug or I/O port hole plug, follow these steps: a. From the outside of the back cover, pull on the hole plug. b.
Maintenance Install DC power hole plug Install foam pads Install foam pad Install I/O port hole plug Install foam pad Install foam pads Figure 6–12: Foam pad and hole plug locations on the back cover c. Place the back cover on a soft surface with the BNC connector openings facing away from you. d. Dress the battery wires to the left side of the back cover to provide clearance for the chassis. e. While inserting the BNC connectors into their openings, lower the chassis into the back cover. f.
Maintenance Retain connectors between pins Locate ferrite bead in cavity Dress wires from battery pack through slots Figure 6–13: Routing the battery wires 6–22 THS710A, THS720A, THS730A & THS720P Service Manual
Maintenance Complete Disassembly You will need a 1@8 inch flat-bladed screwdriver and needle-nose pliers to remove modules mounted to the the chassis. Removal. First, remove the front cover and switch mat using the procedure on page 6–11. Next, remove the chassis assembly using the procedure on page 6–19. Then, use the following procedure to disassemble the chassis. STOP.
Maintenance Unplug connectors Battery cable Unplug connectors 6 5 4 3 1 2 Display module cable Lift here Figure 6–14: Removing the main board and switch flex-circuit assembly 4. To remove the switch flex-circuit assembly from the main board, follow these steps: a. With the main board laying flat from the previous step, raise the switch flex-circuit assembly to an upright position. b.
Maintenance Installation. Use this procedure to reassemble the entire instrument. 1. Check that the ten foam pads on the chassis are correctly installed. The foam pads that surround the display module should be aligned to locating marks in the chassis. Refer to Figure 6–15 for the locations of all the foam pads. Typical locating marks Align this foam pad with bottom edge of chassis Figure 6–15: Foam pad locations on the chassis 2.
Maintenance 5. To prepare the main board and switch flex circuit board for installation into the chassis, follow these steps: a. Fold the switch flex-circuit assembly toward you. b. Dress the battery wires away from you. c. Dress the two coaxial cables that will connect to the BNC connectors to a position under the main board. d. Dress the two wires that will connect to the banana jacks to a position under the main board. 6.
Maintenance Insert circuit board tabs into chassis holes Route battery cable into slot in chassis (not shown) Figure 6–16: Reassembling the chassis 7. To install the display cable, follow these steps: a. Use the 18@ inch flat-bladed screwdriver to open the connector on the main board. b. With the conductive contacts facing away from the main board, insert the display cable into its connector. c.
Maintenance Troubleshooting This section contains information and procedures to help you isolate a defective module in the TekScope instrument. WARNING. Before doing this or any other procedure in this manual, read the General Safety Summary and Service Safety Summary found at the beginning of this manual. Also, to prevent possible injury to service personnel or damage to electrical components, read Preventing ESD on page 6–1.
Maintenance H Displayed information is interrupted by static horizontal or vertical lines or stripes 3. If (after a short wait) you can see that the display operates normally but the display backlight does not turn on, then skip to Backlight on page 6–32. 4. If the instrument does not appear to turn on (no display backlight, no sound of relay clicks, no displayed information), then continue with step 5. 5. Disconnect the AC adapter from the instrument.
Maintenance 8. With the AC adapter still disconnected, use a DMM to measure the DC voltage at the battery connector. Follow the instructions in the table below. Voltage Measurement at Battery Connector Instructions Approximately 0 VDC Check that the battery is installed correctly. Remove the battery and measure its voltage. You should measure an open-circuit voltage >4.8 VDC across a fully charged battery. If the battery is charged, the battery contacts inside the back cover are probably defective.
Maintenance 12. Using a bent paper clip, momentarily short pins 15 and 17 of the connector to bypass the ON/STBY switch as shown in Figure 6–18. Follow the instructions in the table below. Instrument Behavior Instructions Instrument turns on Inspect and/or clean the switch flex-circuit assembly and the switch mat. If cleaning does not solve the problem, one or the other are defective. Replace them both. Instrument does not turn on The main board is probably defective. Replace it.
Maintenance Backlight Follow these steps to troubleshoot a nonfunctional backlight. 1. Remove the front cover using the procedure Front Cover on page 6–11. 2. Turn the instrument on, remove the switch mat, and then fold the switch flex-circuit assembly toward you to access the inverter board. WARNING. To avoid electrical shock, do not touch the two-wire output connector of the inverter board. The output connector is the one closest to the display module. 3.
Maintenance 5. Hold the probe tip above the output connector of the inverter board. Do not touch the probe tip to either of the conductors in the connector. Follow the instructions in the table below. Display Oscilloscope Display Instructions No signal displayed The inverter board is probably defective. Replace it. Approximately 40 kHz sinewave displayed The display module is probably defective. Replace it. Follow these steps to troubleshoot a nonfunctional display. 1.
Maintenance Signal at Loose End of Display Cable Description Pin 7 –10 VDC to –22 VDC Pin 8 0 V (ground) Pin 9 +5 VDC Pin 10 1.89 MHz clock (528 ns period), ≈ 50% duty cycle, appears in bursts, high = 5 V, low = 0 V Pin 11 19.3 kHz clock (51.7 ms period), ≈ 16% duty cycle, high = 5 V, low = 0 V Pin 12 (closest to BNC end of instrument) 75.5 Hz clock (13.2 ms period), ≈ 0.4% duty cycle, high = 5 V, low = 0 V 7.
Maintenance Executing Diagnostics Follow these steps to troubleshoot using diagnostics. 1. To execute the internal diagnostic tests, remove all input signals from the instrument and then perform the following steps: SCOPE UTILITY System Diag Loop Once Execute — OK Run Test 2. A dialog box displays the result when the diagnostic tests completes. If any test fails, the main board is probably defective. Replace it. 3. If all tests pass, press the CLEAR MENU button to continue operation. 4.
Maintenance Input Connections Follow these steps to troubleshoot the input connections only if the following condition is true: the instrument appears to function normally in every way except you have determined that the channel 1, channel 2, or DMM signal is not getting into the instrument as expected. 1. Remove the front cover using the procedure Front Cover on page 6–11. 2. Remove the chassis assembly from the back cover using the procedure Back Cover on page 6–19. 3.
Maintenance Other Troubleshooting Use these techniques to troubleshoot other parts of the instrument. Buttons. Press each of the front-panel buttons to verify that it operates properly. The table below lists the buttons that depend on a particular instrument state for you to see an effect when the button is pressed. Unless noted otherwise, the instrument should be in scope mode for this test.
Maintenance PROBE COMP Output. When the instrument is on, the PROBE COMP output should generate a square wave, approximately 5 V in amplitude, at a 1.2 kHz frequency. Use the oscilloscope and a 10X probe to probe this output. If the signal is not present, the main board is probably defective. Replace it. RS-232 Port. Verify that the RS-232 port operates properly. The easiest way to test the port is to make a hard copy with a compatible printer and RS-232 cable.
Maintenance Battery and External Power. Verify the battery and external power with the following procedure: NOTE. If the instrument runs normally under battery power but only for a short time, the battery may have lost its capacity to hold a charge. You may be able to recover some of its capacity by repeatedly charging and then completely discharging the battery several times. If several charge/discharge cycles do not improve the battery life, it should be replaced. 1.
Maintenance Unpacking and Repacking Instructions This section contains the information needed to unpack the TekScope instrument and repack it for shipment or storage. Unpacking The TekScope instrument and its standard accessories are carefully packed at the factory in a padded case, which is enclosed in a shipping carton. If, upon receipt, damage to the shipping carton is evident, notify the shipper. Tektronix, Inc. is not responsible for damage caused during shipping.
Options The TekScope instrument options provide AC adapters, User Manuals, and Reference Manuals for international customers. Table 7–1 describes these options.
Options 7–2 THS710A, THS720A, THS730A & THS720P Service Manual
Electrical Parts List Refer to the Mechanical Parts List chapter for a complete listing and description of replaceable parts for the TekScope instrument.
Electrical Parts List 8–2 THS710A, THS720A, THS730A & THS720P Service Manual
Diagrams See Figure 3–1 on page 3–2 for a block/interconnect diagram of the TekScope instrument. There are no additional diagrams in this chapter.
Diagrams 9–2 THS710A, THS720A, THS730A & THS720P Service Manual
Mechanical Parts List This section contains a list of the replaceable modules for the TekScope instrument. 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 products are sometimes made to accommodate improved components as they become available and to give you the benefit of the latest improvements.
Mechanical Parts List Module Servicing Modules can be serviced by selecting one of the following three options. Contact your local Tektronix service center or representative for repair assistance. Module Exchange. In some cases you may exchange your module for a remanufactured module. These modules cost significantly less than new modules and meet the same factory specifications. For more information about the module exchange program, call 1-800-TEK-WIDE, extension 6630. New Modules.
Mechanical Parts List Manufacturers Cross Index Mfr. Code Manufacturer Address City, State, Zip Code 0BL82 CRT SCIENTIFIC 14746 RAYMER ST VAN NUYS, CA 91405 0KB01 STAUFFER SUPPLY CO. 810 SE SHERMAN PORTLAND, OR 97214-4657 1DM20 PARLEX CORP. 7 INDUSTRIAL WAY SALEM, NH 03079 22670 GM NAMEPLATE, INC. 2040 15TH AVENUE WEST SEATTLE, WA 98119-2783 53279 XENTEK, INC 1770 LA COSTA MEADOW DR. SAN MARCOS, CA 92069 80009 TEKTRONIX, INC. P.O.
Mechanical Parts List Replaceable Parts List Fig. & Index Number Tektronix Part Number Serial No. Effective Serial No. Discont’d Qty Name & Description Mfr. Code Mfr.
Mechanical Parts List 1 2 3 22 4 9 5 6 7 8 21 9 9 20 9 9 19 10 11 18 9 12 17 16 13 12 14 15 Figure 10–1: Exploded diagram THS710A, THS720A, THS730A & THS720P Service Manual 10–5
Mechanical Parts List Table 10–1 lists the replaceable standard accessories for the TekScope instrument and the instrument options that included them in the original shipment. These accessories are not shown in Figure 10–1.
Mechanical Parts List Table 10–1: Replaceable standard accessories (Cont.
Mechanical Parts List 10–8 THS710A, THS720A, THS730A & THS720P Service Manual
