Page 1
Service Manual
THS710A, THS720A,
THS730A & THS720P
TekScopet
070-9752-02
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.
Page 2
Copyright © Tektronix. All rights reserved. Licensed software products are owned by Tektronix or its subsidiaries or
suppliers, and are protected by national copyright laws and international treaty provisions.
Tektronix products are covered by U.S. and foreign patent s, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
Tek Secure is a registered trademark of Tektronix, Inc.
TekTools, TekScope, and IsolatedChannel are trademarks of Tektronix, Inc.
Pursuant to DFARS 252.227-7013(e), Tektronix Inc. hereby grants to the Government a nonexclusive, paid-up license
throughout the world of the scope set forth therein for Government purposes for any commercial manuals provided by
Tektronix Inc. under this contract.
Contacting Tektronix
Tektronix, Inc.
14200 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA
For product information, sales, service, and technical support:
H In North America, call 1-800-833-9200.
H Worldwide, visit www.tektronix.com to find contacts in your area.
Page 3
Warranty 16
Tektronix warrants that the product will be free from defects in materials and workmanship for a period of thre e
(3) years from the date of original purchase from an authorized Tektronix distributor. If the 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. Parts, modules and replacement products used by Tektronix for warranty work may
be new or reconditioned to like new performance. All replaced parts, modules and products become the property
of Tektronix.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration
of the warranty period and make suitable arrangements for the performance of service. Customer shall be
responsible for packaging and shipping the defective product to the service center designated by Tektronix,
shipping charges prepaid, and with a copy of customer proof of purchase. Tektronix shall pay for the return of the
product to Customer if the shipment is to a location within the country in which the Tektronix service center is
located. Customer shall be responsible for paying all shipping charges, duties, taxes, and any other charges for
products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate
maintenance and care. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage
resulting from attempts by personnel other than Tektronix representatives to install, repair or service the product;
b) to repair damage resulting from improper use or connection to incompatible equipment; c) to repair any
damage or malfunction caused by the use of non-Tektronix supplies; or d) to service a product that has been
modified or integrated with other products when the effect of such modification or integra tion increases the time
or difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THE PRODUCT IN LIEU OF ANY
OTHER WARRANTIES, EXPRESS OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY
IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
TEKTRONIX’ RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND
EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY.
TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL,
OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS
ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.
Page 4
Page 5
Table of Contents
General Safety Summary v...................................
Service Safety Summary vii....................................
Preface ix...................................................
Related Manuals ix.................................................
Conventions x....................................................
Specifications 1.............................................
Operating Information 15.....................................
Internal and External Power Sources 15.................................
Understanding the Front Panel 17......................................
Connecting and Using the Probes 22...................................
Theory of Operation 25.......................................
Main Board 25.....................................................
Inverter Board 25...................................................
Display Module 26.................................................
Switch Assembly 26................................................
Performance V erification 27...................................
Test Record 28.....................................................
Performance Verification Procedures 30.................................
Adjustment Procedures 51.....................................
Required Equipment 51..............................................
Overview of the Adjustment Process 52.................................
Accessing the Adjustment-Lockout Jumper 53...........................
Oscilloscope Adjustment 55..........................................
Meter Adjustment 58................................................
Replacing the Adjustment-Lockout Jumper 61............................
Maintenance 63..............................................
Preparation 63.....................................................
Preventing ESD 63.................................................
Inspection and Cleaning 64...........................................
Removal and Installation Procedures 67.................................
Troubleshooting 90.................................................
Unpacking and Repacking Instructions 102...............................
Options 103..................................................
Electrical Parts List 105........................................
Diagrams 107.................................................
Mechanical Parts List 109......................................
Parts Ordering Information 109.........................................
Using the Replaceable Parts List 110....................................
THS710A, THS720A, THS730A & THS720P Service Manual
i
Page 6
Table of Contents
List of Figures
Figure 1: Removing and replacing the battery 16..................
Figure 2: AC adapter attachment 16.............................
Figure 3: Typical scope-mode display 17.........................
Figure 4: Typical meter-mode display 18.........................
Figure 5: Connector locations 22................................
Figure 6: Module-level block diagram 26.........................
Figure 7: Location of adjustment-lockout jumper 54...............
Figure 8: Oscilloscope adjustment setups 56......................
Figure 9: Meter adjustment setups 59...........................
Figure 10: Relocating the adjustment-lockout jumper 61...........
Figure 11: Removing the tilt stand 70............................
Figure 12: Installing the tilt stand 71............................
Figure 13: Installing a new front-panel label 72...................
Figure 14: Removing the battery door 74.........................
Figure 15: Assembling a new front cover 75......................
Figure 16: Installing the gasket 76..............................
Figure 17: Installing the handle 77..............................
Figure 18: Removing the display module 79......................
Figure 19: Opening the display cable connector 80................
Figure 20: Routing cables to the inverter board 81.................
Figure 21: Lifting the chassis 82................................
Figure 22: Foam pad and hole plug locations on the back cover 83...
Figure 23: Routing the battery wires 84..........................
Figure 24: Removing the main board and switch flex-circuit
assembly 86..............................................
Figure 25: Foam pad locations on the chassis 87...................
Figure 26: Reassembling the chassis 89..........................
Figure 27: Battery connector location 91.........................
Figure 28: Bypassing the ON/STBY switch 93....................
Figure 29: Exploded diagram 113................................
ii
THS710A, THS720A, THS730A & THS720P Service Manual
Page 7
List of Tables
Table of Contents
Table 1: Oscilloscope specifications 1..........................
T able 2: DMM specifications 8................................
T able 3: General specifications 10..............................
Table 4: Summary of oscilloscope adjustment steps 55.............
T able 5: Summary of meter adjustment steps 58..................
T able 6: Internal inspection check list 65........................
Table 7: Removal and installation procedures 68..................
Table 8: TekScope instrument options 103........................
T able 9: Replaceable standard accessories 114.....................
THS710A, THS720A, THS730A & THS720P Service Manual
iii
Page 8
Table of Contents
iv
THS710A, THS720A, THS730A & THS720P Service Manual
Page 9
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.
Connect and Disconnect Properly. Do not connect or disconnect probes or test
leads while they are connected to a voltage source.
Ground the Product. This product is grounded through the grounding conductor
of the power cord. To avoid electric shock, the grounding conductor must be
connected to earth ground. Before making connections to the input or output
terminals of the product, ensure that the product is properly grounded.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product. Consult the product manual for further ratings
information before making connections to the product.
Do not apply a potential to any terminal, including the common terminal, that
exceeds the maximum rating of that terminal.
Replace Batteries Properly. Replace batteries only with the specified type and
rating.
Recharge Batteries Properly. Recharge batteries for the recommended charge
cycle only.
Use Proper AC Adapter. Use only the AC adapter specified for this product.
Do Not Operate Without Covers. Do not operate this product with covers or panels
removed.
Avoid Exposed Circuitry. Do not touch exposed connections and components
when power is present.
Do Not Operate With Suspected Failures. If you suspect there is damage to this
product, have it inspected by qualified service personnel.
Do Not Operate in Wet/Damp Conditions.
Do Not Operate in an Explosive Atmosphere.
THS710A, THS720A, THS730A & THS720P Service Manual
v
Page 10
General Safety Summary
Terms in this Manual
Symbols and Terms
on the Product
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.
These terms may appear on the product:
H DANGER indicates an injury hazard immediately accessible as you read the
marking.
H WARNING indicates an injury hazard not immediately accessible as you
read the marking.
H CAUTION indicates a hazard to property including the product.
The following symbol(s) may appear on the product:
CAUTION
Refer to Manual
WARNING
High Voltage
Double
Insulated
Protective Ground
(Earth) Terminal
vi
THS710A, THS720A, THS730A & THS720P Service Manual
Page 11
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. Disconnect power, remove battery (if applicable), and
disconnect test leads before removing protective panels, soldering, or replacing
components.
To avoid electric shock, do not touch exposed connections.
THS710A, THS720A, THS730A & THS720P Service Manual
vii
Page 12
Service Safety Summary
viii
THS710A, THS720A, THS730A & THS720P Service Manual
Page 13
Preface
Related Manuals
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.
Additional documentation for the instrument is contained in the related manuals
listed below.
User Manual
Language
English 070-9731-XX 070-9741-XX 070-9751-XX
French 070-9732-XX 070-9742-XX
German 070-9733-XX 070-9743-XX
Italian 070-9734-XX 070-9744-XX
Korean 070-9735-XX 070-9745-XX
Portuguese 070-9736-XX 070-9746-XX
Spanish 070-9737-XX 070-9747-XX
Simplified Chinese 070-9738-XX 070-9748-XX
Traditional
Chinese
Japanese 070-9740-XX 070-9799-00
Part Number
070-9739-XX 070-9749-XX
Reference
Part Number
Programmer Manual
Part Number
THS710A, THS720A, THS730A & THS720P Service Manual
ix
Page 14
Preface
Conventions
In the Performance Verification, Adjustments,andMaintenance 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.
2. Press this button on the front
panel.
3. Press this
bezel button.
6. 7. —
8. 9. 10.
4. Press the
bezel button
again until this
selection is highlighted.
5. Use the
+
the value for a
parameter.
/-- rocker to set
x
THS710A, THS720A, THS730A & THS720P Service Manual
Page 15
Specifications
g
q
g
BNC
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. All
specifications assume horizontal MAG is off, unless noted otherwise. To meet
specifications, 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 Compensate Signal Path operation, accessible through
the utility menu, if the ambient temperature changes by more than 5° C.
Table 1: Oscilloscope specifications
Acquisition
Acquisition Modes Sample (Normal), Peak detect, Envelope, and Average
Acquisition Rate,
typical
Single Sequence Acquisition Mode Acquisition Stops After
Up to 25 waveforms per second (2 channels, sample acquisition mode,
MAG on, no measurements)
Sample, Peak Detect Single acquisition, one or two
channels simultaneously
Average, Envelope N acquisitions, one or two chan-
nels simultaneously, N is settable
from 2 to 256 or ∞
Inputs
Input Coupling DC, AC, or GND
Input Impedance,
DC Coupled
Maximum Voltage Overvoltage Category Maximum Voltage
Between Signal and
Common at Input
THS710A, THS720A, THS730A & THS720P Service Manual
1MΩ ±1% in parallel with 25 pF ±2pF
CAT II Environment (refer to
page 13)
CAT III Environment (refer to
page 13)
For steady-state sinusoidal waveforms, derate at 20 dB/decade above
100 kHz to 13 V
Category description on page 13.
at 3 MHz and above. Also, refer to Overvoltage
pk
300 V
150 V
RMS
RMS
1
Page 16
Specifications
g
peBa
lopeBandwidth
,
Table 1: Oscilloscope specifications (Cont.)
Inputs
Maximum Voltage
Between Common
and Earth Ground
at BNC
600 V
RMS
accessories
30 V
, 42.4 Vpk, using noninsulated connectors and acessories
RMS
(CAT II) or 300 V
(CAT III), using rated connectors or
RMS
Maximum Voltage,
30 V
, 42.4 Vpk, using noninsulated connectors and acessories
RMS
Channel-to-Channel
Commons
Channel-to-Channel
Common Mode
Rejection, typical
100:1 at frequencies ≤50 MHz, measured on MATH Ch1 -- Ch2
waveform, with test signal applied between signal and common of both
channels, and with the same VOLTS/DIV and coupling settings on each
channel
Channel-to-Channel
Crosstalk, typical
≥100:1 at 50 MHz, measured on one channel, with test signal applied
between signal and common of the other channel, and with the same
VOLTS/DIV and coupling settings on each channel
Common to Chassis
55 pF
Capacitance, typical
Vertical
Number of Channels 2
Digitizers 8 bit resolution, separate digitizers for each channel sample
simultaneously
VOLTS/DIV Range 5 mV/div to 50 V/div at input BNC
Polarity Normal and Invert
Position Range ±10 divisions
n Analog Bandwidth THS710A THS720A THS720P THS730A
at BNC, DC Coupled
(typical at 5 mV/div,
guaranteed at all
other settings)
Peak Detect or Envelo
ndwidth,
,
typical (25 MS/s or
slower)
60 MHz at input
BNC
100 MHz at
input BNC
(90 MHz above
35° C)
100 MHz at
input BNC
(90 MHz above
35° C)
200 MHz at
input BNC
(180 MHz
above 35° C)
THS710A THS720A THS720P THS730A
50 MHz
75 MHz 75 MHz 85 MHz
Analog Bandwidth
Selectable between 20 MHz or full
Limit, typical
Lower Frequency
Limit, AC Coupled,
≤10 Hz at BNC, reduced by a factor of ten when using a 10X passive
probe
typical
Rise Time at BNC, THS710A THS720A THS720P THS730A
typical
2
5.8 ns 3.5 ns 3.5 ns 1.75 ns
THS710A, THS720A, THS730A & THS720P Service Manual
Page 17
Table 1: Oscilloscope specifications (Cont.)
forms
p
g
/
g
ggy
,
ggy
,
Vertical
Peak Detect or Envelope Pulse Response,
typical
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 Measurement Type Accuracy
Accuracy, Average
Acquisition Mode
Using ≥16 Wave-
Captures 50% or greater amplitude of pulses ≥ 8nswide(≥ 20 ns wide
at 500 ns/div)
Absolute voltage measurements ±[2% × |reading +
(position × volts/div)| +
(0.1 div × volts/div)]
Specifications
Delta voltage between any two
waveforms acquired under same
setup
DC Measurement
Accuracy, Sample
Acq. Mode, typical
Horizontal
Sample Rate Range THS710A THS720A THS720P THS730A
Record Length 2500 samples for each channel
SEC/DIV Range THS710A THS720A THS720P THS730A
(including MAG)
n Sample Rate and
Delay Time Accuracy
Delay Time Range Zero to 50 s
Internal Trigger
n Trigger Sensitivity, Coupling Sensitivity
Edge Trigger Type
(THS710A, THS720A,
and THS720P)
±[2% × |reading + (position × volts/div)| + (0.15 div × volts/div) +
0.6 mV]
5 S/s to
250 MS/s, in a
1.25, 2.5, 5
sequence
10 ns/div to
50 s/div
±200 ppm over any ≥1 ms time interval
DC
5 S/s to
500 MS/s, in a
1.25, 2.5, 5
sequence
5 ns/div to
50 s/div
±[2% × |reading| +
(0.05 div × volts/div)]
5 S/s to
500 MS/s, in a
1.25, 2.5, 5
sequence
5 ns/div to
50 s/div
0.35 div from DC to 50 MHz,
increasing to 1 div at 100 MHz
(90 MHz above 35° C)
5S/sto1GS/s,
in a 1.25, 2.5, 5
sequence
2 ns/div to
50 s/div
n Trigger Sensitivity, Coupling Sensitivity
Edge Trigger Type
(THS730A)
THS710A, THS720A, THS730A & THS720P Service Manual
DC 0.35 div from DC to 50 MHz,
increasing to 1.5 div at 200 MHz
(180 MHz above 35° C)
3
Page 18
Specifications
ggy
,
t
ypica
l
,
Table 1: Oscilloscope specifications (Cont.)
Internal Trigger
Trigger Sensitivity, Coupling Sensitivity
Edge Trigger Type,
Trigger Level Range ±4 divisions from center of screen
Motor Trigger Level
Range (THS720P)
Trigger Level
Accuracy, typical
SET LEVEL TO 50%,
typical
Width Range, Pulse
Trigger Type, typical
Width Tolerance
Range, Pulse Trigger
Type, typical
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
0.1 to 5 divisions from center screen, polarity depends on slope
selection
±0.2 divisions, for signals having rise and fall times ≥20 ns
Operates with input signals ≥50 Hz
99 ns to 1 s, with resolution of 33 ns or approximately 1% of setting
(whichever is greater)
5%, 10%, 15%, or 20%
Sensitivity, Video
Trigger Type, typical
Signal Formats and
Composite video signal with negative sync pulse amplitude from 0.6
to 2.5 divisions
Broadcast systems Supports NTSC, PAL, and
Field Rates, Video
Trigger Type
Interlaced
Non-interlaced Trigger on selected line or any line
Line Rates 15 kHz to 65 kHz, in five ranges
Holdoff Range 495 ns to 10 s
External Trigger
External Trigger, Max-
600 V
CAT II or 300 V
RMS
imum Input Voltage
External Trigger
DC only
Coupling
External Trigger
+0.2 V or +2 V, selectable
Levels
External Trigger
Sensitivity
500 mV
fromDCto1MHz,increasingto1V
p-p
signal centered at selected trigger level
SECAM
Trigger on selected line of odd
field, selected line of even field, or
any line
CAT III (refer to page 13)
RMS
at 5 MHz, with
p-p
4
THS710A, THS720A, THS730A & THS720P Service Manual
Page 19
Table 1: Oscilloscope specifications (Cont.)
Measurements
Cursors Voltage difference between cursors (ΔV)
Time difference between cursors (ΔT)
Reciprocal of ΔTinHertz(1/ΔT)
Phase difference between cursors (ΔDegrees)
Specifications
Automated
Measurements
Amplitude, Burst Width, Cycle Mean, Cycle RMS, Fall Time,
Frequency, High, Low, Max, Mean, Min, Negative Duty Cycle, Negative
Overshoot, Negative Width, Pk -- Pk, Period, Positive Duty Cycle,
Positive Overshoot, Positive Width, Rise Time, and RMS
Voltage and Current Harmonics (THS720P)
Number of Harmonics First 31 harmonics of signal with fundamental frequency between
30 Hz and 450 Hz
Harmonics Amplitude
Accuracy
Accuracies below are stated as a percent of the fundamental amplitude
and are valid only if peak-to-peak amplitude is ≥4 di v isions and number
of averages ≥16
Fundamental 2--11 12 -- 21 22 -- 31
±2.5% ±2.5% ±4% ±4%
Harmonics Phase Fundamental 2--11 12 -- 21 22 -- 31
Accuracy
— ±4 ° ±8 ° ±8 °
THD-F Measurement Total harmonic distortion relative to the fundamental amplitude
THD-F =
2
Ꭹ
V
RMS
V
− V
f
2
f
2
Ꭹ
A
RMS
or
A
− A
f
2
f
THD-F Accuracy ±4%
THD-R Measurement Total harmonic distortion relative to the RMS amplitude
THD-R =
2
Ꭹ
V
RMS
2
− V
f
V
RMS
2
Ꭹ
A
RMS
or
2
− A
f
A
RMS
THD-R Accuracy ±4%
Frequency Accuracy ±0.2% of reading
Power Measurements (THS720P)
True Power
Measurement
W =
1
ᒑ
×
Vn× A
n
n
n
measured over an integral number of cycles that
contain n sample points
Apparent Power
VA = V
RMS
× A
RMS
Measurement
Reactive Power
Measurement
Power Measurements
VAR = (VA)2− W
Ꭹ
±4% at the BNCs (not including probe uncertainty)
2
Accuracy
THS710A, THS720A, THS730A & THS720P Service Manual
5
Page 20
Specifications
g
,
g
Table 1: Oscilloscope specifications (Cont.)
Power Measurements (THS720P)
PF Measurement
Power factor (PF) =
θ Measurement θ 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 θ
Power Factor Mea-
±0.05
surements Accuracy
With P6117 Probe
Analog Bandwidth, THS710A THS720A THS720P THS730A
DC Coupled
60 MHz 100 MHz
true power
apparent power
100 MHz
=
W
VA
200 MHz
(90 MHz above
35° C)
(90 MHz above
35° C)
Probe Attenuation 10X
Maximum Voltage Overvoltage Category Maximum Voltage
Between Probe Tip
and Reference Lead
CAT II Environment (refer to
page 13)
CAT III Environment (refer to
300 V
150 V
RMS
RMS
page 13)
For steady-state sinusoidal waveforms, derate at 20 dB/decade above
900 kHz to 13 V
at 27 MHz and above. Also, refer to Overvoltage
pk
Category description on page 13.
Maximum Voltage
30 V
RMS
, 42.4 V
pk
Between Reference
Lead and Earth
Ground Using P6117
Probe
Maximum Voltage,
30 V
RMS
, 42.4 V
pk
Channel-to-Channel
Reference Leads
Using P6117 Probe
(180 MHz
above 35° C)
6
THS710A, THS720A, THS730A & THS720P Service Manual
Page 21
Specifications
g
,
g
DCCoupled
g
andReferenceLea
d
g
LeadandEart
h
Table 1: Oscilloscope specifications (Cont.)
With P5102 Probe
Analog Bandwidth, THS710A THS720A THS720P THS730A
DC Coupled
60 MHz 100 MHz
100 MHz
100 MHz
(90 MHz above
35° C)
(90 MHz above
35° C)
Probe Attenuation 10X
Maximum Voltage Overvoltage Category Maximum Voltage
Between Probe Tip
and Reference Lead,
CAT II Environment (refer to
page 13)
CAT III Environment (refer to
1000 V
600 V
RMS
RMS
page 13)
Maximum Voltage
Between Probe Tip
AC Coupled
Maximum Voltage
Between Reference
Ground
Overvoltage Category Maximum Voltage
CAT II Environment ±1000 V
,
CAT III Environment
±600 V
DC
Overvoltage Category Maximum Voltage
CAT II Environment 600 V
CAT III Environment 300 V
RMS
RMS
DC
THS710A, THS720A, THS730A & THS720P Service Manual
7
Page 22
Specifications
g
g
Groun
d
g
Table 2: DMM specifications
General
Resolution 33⁄4digit, 4000 count full scale reading except as noted
Input Resistance, AC
or DC Voltage
Input Capacitance,
AC or DC Voltage,
typical
Maximum Voltage Overvoltage Category Maximum Voltage
Between DMM and
COM Inputs
Maximum Voltage Overvoltage Category Maximum Voltage
Between DMM or
COM Input and Earth
DC Voltage
Ranges and Range Resolution
Resolution
n Accuracy ±(0.5% of reading + 5 counts)
Normal Mode
Rejection, typical
Common Mode
Rejection, typical
10 MΩ ±10%
≤100 pF
CAT I Environment (refer to
640 V
RMS
(880 VDC)
page 13)
CAT II Environment (refer to
600 V
RMS
page 13)
CAT III Environment (refer to
300 V
RMS
page 13)
CAT I Environment (refer to
640 V
RMS
(880 VDC)
page 13)
CAT II Environment (refer to
600 V
RMS
page 13)
CAT III Environment (refer to
300 V
RMS
page 13)
400.0 mV 0.1 mV
4.000 V 1mV
40.00 V 10 mV
400.0 V 100 mV
880 V 1V
Rejects AC signals by >60 dB at 50 Hz or 60 Hz (user selectable)
Rejects AC signals by >100 dB at 50 Hz or 60 Hz (user selectable)
8
THS710A, THS720A, THS730A & THS720P Service Manual
Page 23
Specifications
g
y
g
y
g
Mea
t
ypica
l
Table 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 Range Resolution
Resolution
n Accuracy Input Waveform Maximum Error
(40Hzto500Hz)
Common Mode
Rejection, typical
Ω/Resistance
Ranges and Range Resolution
Resolution
n Accuracy Range Maximum Error
Bias Voltage for Full Range Full Scale Bias Voltage
Scale Resistance
surement,
400.0 mV
4.000 V 1mV
40.00 V 10 mV
400.0 V 100 mV
640 V 1V
Sinusoidal waveforms ±(2% of reading + 5 counts)
Nonsinusoidal waveforms with
crest factor up to 3
Rejects AC signals by >60 dB at DC, 50 Hz, and 60 Hz
400.0 Ω 0.1 Ω
4.000 kΩ 1 Ω
40.00 kΩ 10 Ω
400.0 kΩ 100 Ω
4.000 MΩ 1kΩ
40.00 MΩ 10 kΩ
All ranges except 40 MΩ ±(0.5% of reading + 2 counts)
40 MΩ ±(2% of reading + 5 counts) for
400.0 Ω 350 mV
4.000 kΩ 200 mV
40.00 kΩ 350 mV
400.0 kΩ 350 mV
4.000 MΩ 400 mV
40.00 MΩ 1.10 V
0.1 mV
±(4% of reading + 5 counts)
≤60% relative humidity
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Specifications
pg,
Table 2: DMM specifications (Cont.)
Ω/Resistance
Open Circuit Voltage, Range Open Circuit Voltage
typical
Continuity Check
Indication An audible tone is generated when measured resistance is below 50
Open Circuit Voltage,
typical
Test Current, typical 1mA
Diode Check
Range Zero to 2 V, measures forward voltage drop of semiconductor junction
Voltage Accuracy,
typical
Open Circuit Voltage,
typical
Test Current, typical 1mA
Data Logger
Horizontal Scale
Range
Vertical Zoom Range 2X, 5X, or 10X
400.0 Ω 4.8 V
All other ranges ≤1.2 V
Ω,typical
4V
±25%
4V
30 s/div to 24 hours/div (4 minutes to 8 days, full scale)
10
Table 3: General specifications
Display
Display Type 4.7 in (120 mm) diagonal liquid crystal
Display Resolution 320 horizontal by 240 vertical pixels
Display Contrast Adjustable, temperature compensated
Backlight Intensity,
typical
35 cd/m
2
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Specifications
,yp
Table 3: General specifications (Cont.)
RS-232 Interface
Device Type DTE. at RJ-45 connector
Pinout Signal Pin Number at
9-pin Null
Modem Adapter
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
Frequency, typical 1.2 kHz
Power Source
Battery Replaceable Ni-Cd battery pack
Battery Life, typical Approximately two hours of continuous use from a full charge
Low Battery Indication, typical
Battery Saver Standby Time-out and Backlight Time-out extend battery life. Time-out
Battery Charging
Time, typical
External Power 12 VDC nominal, center positive; Operates with input from 10 VDC to
5.0 V into ≥1MΩ load
Low battery message first appears approximately ten minutes before
the instrument powers off automatically
ranges from 1 minute to 15 minutes, or off.
With TekScope instrument operating
With TekScope instrument turned
off
In external charger 1.5 hours
15 VDC
9 hours
9 hours
Pin Number at
RJ-45
Connector
The DC INPUT disconnects itself automatically if >15 VDC is applied.
If this occurs, disconnect the overvoltage and then reconnect to a
voltage in the proper range.
Memory Retention,
typical
Fuse This instrument has no user-replaceable fuses
THS710A, THS720A, THS730A & THS720P Service Manual
All memory is retained indefinitely with battery removed and without
external power applied.
11
Page 26
Specifications
p
y
g
Table 3: General specifications (Cont.)
Environmental
Temperature Operating -- 1 0 ° Cto+50° C
Nonoperating -- 2 0 ° Cto+60° C
Humidity +40° C or below ≤95% relative humidity
+41° Cto+50° C ≤75% relative humudity
Altitude Operating 2,000 m
Nonoperating 15,000 m
Random Vibration Operating 2.66 g
10 minutes on each axis
Nonoperating 3.48 g
10 minutes on each axis
Drop Resistance,
Survives a 30 in (76 cm) drop onto concrete with only cosmetic damage
typical
Moisture Resistance Meets IEC529, IP43 with DC input hole plug, I/O port hol e plug, and
battery door installed.
Mechanical
Size Height 8.53 in (217 mm)
Width 6.95 in (177 mm)
Depth 2.00 in (50.8 mm)
Weight With battery installed 3.2 lbs (1.5 kg)
With all standard accessories in
7.5 lbs (3.4 kg)
soft carry case
When packaged for domestic
9.0 lbs (4.1 kg)
shipment
Adjustment Interval
The recommended adjustment interval is one year
from 5 Hz to 500 Hz,
RMS
from 5 Hz to 500 Hz,
RMS
12
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Specifications
ggy
Table 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.
CAT II A typical CAT II environment is
the 120/240 V distribution system
within a lab or office. These
environments are fairly well
protected from external high
voltage disturbances.
CAT I A typical CAT II environment is
circuitry inside electrical or electronic equipment that is powered
by a power supply or a battery.
EC Declaration of
Conformity
Meets the intent of Directive 89/336/EEC for Electromagnetic
Compatibility and Low-Voltage Directive 73/23/ECC for Product Safety
as ammended by 93/68/EEC. Compliance was demonstrated to the
following specifications as listed in the official Journal of the European
Communities:
EN 55011 Class A: Radiated and Conducted Emissions
13
EN 50081--1 Emissions:
EN 60555--2 Power Harmonics
EN 50082--1 Immunity:
IEC 801--2 Electrostatic Discharge
IEC 801--3 RF Radiated
2
IEC 801--4 Fast Transients
IEC 801--5 Surge
3
EN 61010--1 Safety
1
Tektronix-supplied ferrite bead required on instrument end of
RS-232 cable
2
Performance criteria: ≤ 5.0 div increase in peak to peak noise
(Sample acquisition mode, full bandwidth); otherwise, ≤ 1.0 div
increase in peak to peak noise
3
Applies to instrument operating with Tektronix-supplied AC
adapter
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Specifications
14
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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 102 of this manual.
Internal and External Power Sources
You can power the TekScope instrument from the internal battery pack or from
the AC adapter (both are standard accessories).
Using the Battery Pack
Before using the battery for the first time, it must be charged. You can use
external power to charge the battery pack while it is in the TekScope instrument.
Or you can charge the battery pack with the optional external battery charger.
Typical battery charging times are listed below.
Configuration Typical Charging Time
Battery pack in TekScope instrument 9 hours
Battery pack in external charger 1.5 hours
You can remove and replace the battery pack without losing any saved
information. The current setup, saved setups, saved waveforms, and saved data
are stored in nonvolatile memory that does not depend on battery power. To
prevent loss of saved information, set the ON/STBY switch to STBY before
removing the battery pack. See Figure 1 for instruction to remove and replace the
battery.
WARNING. To avoid shock hazard, the battery door must remain closed in wet or
damp conditions.
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Operator Information
Battery pack
Figure 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. 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.
External power to
DC INPUT
16
Figure 2: AC adapter attachment
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Page 31
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.
Operator Information
Using Scope Mode
Press the front-panel SCOPE button to enter scope mode. Then, press AUTORANGE to set the vertical, horizontal, and trigger automatically for a usable
display. A typical scope-mode display is shown in Figure 3.
Status line
Graticule
area
Waveform readout lines
Measurement
readout area
Figure 3: Typical scope-mode display
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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 4.
Status line
Measurement
readout areas
Graticule area
Figure 4: Typical meter-mode display
18
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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.
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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.
20
NOTE.InthePerformance Verification, Adjustments, and Maintenance chapters
of this manual, TekScope instrument setups are shown in tables. Refer to
Conventions on page x for information about reading these tables.
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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.
2
31
4
16
15
14
87910111213
5
6
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. SET LEVEL TO 50%. Sets trigger level to midpoint of oscilloscope
waveform.
7. HORIZONTAL POSITION. Adjusts oscilloscope waveform horizontal
position.
8. MAG. Turns 10X horizontal magnification on and off.
9. SEC/DIV. Adjusts waveform horizontal scale factor for oscilloscope or data
logger.
10. VERTICAL POSITION. Adjusts oscilloscope waveform vertical position.
11. WAVEFORM OFF. Removes selected oscilloscope waveform from display.
12. VOLTS/DIV. Adjusts oscilloscope vertical scale factor or meter range.
13. ON/STBY. Selects on or standby. Does not disconnect power from the
instrument.
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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 5.
Top panel
Figure 5: Connector locations
Side panel
22
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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. Repeat these steps for the other probe and channel.
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Operator Information
Attaching the Reference
Leads Correctly
Beware of High Voltages
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.
Understand the voltage ratings for the probes you are using and do not exceed
those ratings. Two ratings are important to know and understand:
H The maximum measurement voltage from the probe tip to the probe
reference lead
H The maximum floating voltage from the probe reference lead to earth ground
These two voltage ratings depend on the probe and your application. Refer to
Specifications beginning on page 1 for more information.
WARNING. To prevent electrical shock, do not exceed the measurement or
floating voltage ratings for the oscilloscope input BNC connector, probe tip,
probe reference lead, DMM input connector, or DMM lead.
24
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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 6.
Main Board
The Main board assembly contains the following oscilloscope and meter
functions.
Oscilloscope Signal Path
Meter Signal Path
Processor System
Display System
Power Supply
Each of the two oscilloscope input signals enters the main board and passes
through an attenuator and buffer amplifier. Then each signal passes through an
isolation interface before reaching the trigger circuitry, a sampler, and a digitizer.
The digitized signals are written into system memory for transfer to the display
system.
The DMM input enters the Main board and passes through a switching network
to select the meter function and range. The DMM signal is then sampled and
digitized.
The processor system contains a 68331 microprocessor that controls the entire
instrument. The processor passes waveforms, meter readings, and text on to the
display system. The processor system also contains flash ROM, system RAM,
and the RS-232, keyboard, and probe compensation interfaces.
The display system, consisting of a display controller and video memory,
processes text and waveforms to refresh the display.
The power supply provides DC power to ciruits on the main board and generates
an AC voltage to provide power to the attenuators and buffer amplifiers across
the isolation interfaces. It also provides +12 V and --20 V for the display module.
Inverter Board
The inverter board generates an AC voltage for the display backlight.
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Theory of Operation
Display Module
Switch Assembly
The display module consists of a liquid crystal display (LCD), a display driver,
and a flourescent backlight.
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.
Battery
Adjustment-
lockout
Not used
12
2
80
EXT
PWR
2
J8
J3
J1
J9
CH 1 CH 2
J7 J6
Main board
PROBE
COMP
8
J5
RS-232
COM
DMM
26
Inverter boardDisplay assembly Switch assembly
2
Figure 6: Module-level block diagram
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17
Page 41
Performance Verification
C
alibra
tionOption(Op
tio
CalibrationOption(Optio
n
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
DC Voltage Source 60 mV to 800 V, ±0.1% accu-
AC Voltage Source 300 mV to 640 V, ±0.5%
Resistance Standard 360 Ω to 36 MΩ, ±0.1%
Leveled Sine Wave Generator 50 kHz and 100 MHz, ±3%
Time Mark Generator 10 ms period, ±50 ppm accu-
Minimum
Requirements
racy
accuracy at 500 Hz
accuracy
amplitude accuracy
racy
Examples
Wavetek 9100 Universal
Calibration System with Oscilloscope Calibration Module
(Option 250)
Fluke 5500AMulti-product
Calibrator with Oscilloscope
n
5500A-SC)
Banana to Banana Cable (two
required)
50 Ω BNC Cable BNCmaletoBNCmale,
50 Ω Feedthrough Termination
Dual Banana to BNC Adapter Banana plugs to BNC female Tektronix part number
Shielded banana jacks on
each end
≈ 36 in (1 m) long
BNC male and female connectors
Tektronix Deluxe Meter Lead
Set (ATLDX1)
Tektronix part number
012-0482-00
Tektronix part number
011-0049-01
103-0090-00
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Performance Verification
Accuracy
Accuracy
Test Record
Serial
Number
Test Passed Failed
Self Test
Oscilloscope Tests Low Limit Test Result High Limit
Channel 1 DC Measurement
Procedure Performed by Date
5mV/div 34.05 mV 35.95 mV
500 mV/div 3.405 V 3.595 V
2V/div 13.62 V 14.38 V
10 V/div 68.1 V 71.9 V
Channel 2 DC Measurement
Channel 1 Bandwidth 425 mV —
Channel 2 Bandwidth 425 mV —
Sample Rate and Delay Time Accuracy -- 4 d i v s +4 divs
Channel 1 Edge Trigger Sensitivity Stable trigger —
Channel 2 Edge Trigger Sensitivity Stable trigger —
5mV/div 34.05 mV 35.95 mV
500 mV/div 3.405 V 3.595 V
2V/div 13.62 V 14.38 V
10 V/div 68.1 V 71.9 V
28
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Performance Verification
DMM Tests Low Limit Test Result High Limit
DC Voltage Accuracy 400 mV range,
60 mV input
59.2 mV 60.8 mV
400 mV range,
360 mV input
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
AC Voltage Accuracy 400 mV range 352.3 mV 367.7 mV
4 V range,
600 mV input
4 V range,
3.6 V input
40 V range 35.23 V 36.77 V
400 V range 352.3 V 367.7 V
640 V range 559 V 593 V
Resistance Accuracy 400 Ω range 358.0 Ω 362.0 Ω
4kΩ range 3.580 kΩ 3.620 kΩ
40 kΩ range,
6kΩ input
40 kΩ range,
36 kΩ input
357.7 mV 362.3 mV
0.583 V 0.617 V
3.523 V 3.677 V
5.95 kΩ 6.05 kΩ
35.80 kΩ 36.20 kΩ
400 kΩ range 358.0 kΩ 362.0 kΩ
4MΩ range 3.580 MΩ 3.620 MΩ
40 MΩ range 35.23 MΩ 36.77 MΩ
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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.
If the ambient temperature changes by more than 5° C, you must perform the
Signal Path Compensation operation again.
The time required to complete the entire procedure is approximately one hour.
WARNING. Some procedures use hazardous voltages. To prevent electrical shock,
always set voltage source outputs to 0 V before making or changing any
interconnections.
Signal Path Compensation
Signal path compensation optimizes the oscilloscope accuracy for the current
ambient temperature. For maximum accuracy, recompensate the signal path if the
ambient temperature changes by 5° Cormore.
To compensate the signal path, perform the following steps:
1. Disconnect any probes or cables from the channel 1 and channel 2 input
BNC connectors.
2. Execute the signal path compensation with the following steps:
SCOPE UTILITY
3. When the signal path compensation is complete, press CLEAR MENU to
resume operation of the TekScope instrument.
System Cal
Signal Path
OK Compensate Signal
Paths
—
30
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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.
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Page 46
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 0V.
2. Set up the TekScope instrument using the following steps:
SCOPE SAVE/
RECALL
CH 1 —
VERTICAL
MENU
ACQUIRE Mode Average Set to 16
MEAS
* You may need to press Select Page to display this selection.
Recall Saved
Setup
OK Recall
Factory
Probe Type Voltage Probe Set to 1X
Select Measrmnt Mean*
OK Select
Measrmnt
Recall Factory
Setup
—
—
—
—
3. Connect the TekScope instrument to the DC voltage source as shown below.
DC voltage
source
+--
Dual banana
to bnc adapter
BNC cable
Ch 1
32
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Performance Verification
4. For each VOL TS/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 V
pos
.
b. Reverse the polarity of the DC voltage source and then record the mean
measurement as V
neg
.
c. Calculate V
diff=Vpos
-- V
and then compare V
neg
to the accuracy
diff
limits in the table.
DC Voltage Source Output
VOLTS/DIV Setting
5mV/div +17.5 mV, --17.5 mV 34.05 mV to 35.95 mV
500 mV/div +1.75 V, --1.75 V 3.405 V to 3.595 V
2V/div +7.00 V, --7.00 V 13.62 V to 14.38 V
10 V/div +35.0 V, --35.0 V 68.1 V to 71.9 V
Levels
Accuracy Limits for V
diff
5. Set DC voltage source output level to 0V.
6. To check channel 2, repeat step 2 substituting CH 2 for CH 1.
7. Press CH 1 and WAVEFORM OFF to remove the channel 1 waveform
from the display.
8. Repeat steps 3 through 5, substituting CH 2 for CH 1, to complete the check
of channel 2.
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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 SAVE/
RECALL
ACQUIRE Mode Average Set to 16
TRIGGER Coupling Noise Reject —
MEAS
* You may need to press Select Page to display this selection.
Recall Saved
Setup
OK Recall
Factory
Gating & High-Low
Setup
Select Measrmnt Pk-Pk*
OK Select
Measrmnt
Recall Factory
Setup
—
High-Low Method Min/Max
—
—
—
2. Connect the TekScope instrument to the leveled sine wave generator as
shown below.
Leveled
sine wave
generator
Output
BNC cable
50 Ω feedthrough
terminator
Ch 1
34
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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. Set the TekScope instrument SEC/DIV to 10 ns/div.
10. Check that the peak-to-peak measurement is ≥425 mV.
11. Press MAG.
12. Proceed to the next test to check the channel 2 bandwidth.
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Page 50
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
* You may need to press Select Page to display this selection.
CH 1
WAVEFORM
OFF
CH 2
TRIGGER Trigger Source Ch2
MEAS
— — —
Gating & High-Low
Setup
Select Measrmnt Pk-Pk*
OK Select
Measrmnt
High-Low Method Min/Max
—
—
2. Connect the TekScope instrument to the leveled sine wave generator as
shown below.
Leveled
sine wave
generator
Output
BNC cable
50 Ω feedthrough
terminator
Ch 2
36
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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. Set the TekScope instrument SEC/DIV to 10 ns/div.
10. Check that the peak-to-peak measurement is ≥425 mV.
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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
OK Recall
Factory
Probe Type Voltage Probe Set to 1X
Recall Factory
Setup
—
—
2. Connect the TekScope instrument to the time mark generator as shown
below.
Time mark
generator
50 Ω feedthrough
terminator
Ch 1
Output
BNC cable
3. Set the time mark generator period to 10 ms.
4. Set the TekScope instrument VOLTS/DIV to 500 mV/div.
5. Use the vertical POSITION rocker to center the test signal on screen.
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Performance Verification
6. Press SET LEVEL TO 50%.
7. Press MAG.
8. Change the TekScope instrument setup using the following steps:
SCOPE
HORIZONTAL M E N U
CLEAR
MENU
Time Base Delayed Runs After
Main
— —
—
9. Set the delayed time base SEC/DIV to 50 ms/div.
10. Change the TekScope instrument setup using the following steps:
SCOPE
HORIZONTAL M E N U
CLEAR
MENU
Time Base Delayed Runs After
Main
— — —
Set delay time to
10 ms
11. Set the delayed time base SEC/DIV to 500 ns/div.
12. Check that the rising edge of the marker crosses the center horizontal
graticule line within ±4 divisions of center graticule.
NOTE. One division of displacement from graticule center corresponds to
a 50 ppm time base error.
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Performance Verification
Check Oscilloscope
Channel 1 Edge Trigger
Sensitivity
This test checks the edge trigger sensitivity for channel 1.
1. Set up the TekScope instrument using the following steps:
SCOPE SAVE/
RECALL
ACQUIRE Mode Average Set to 16
TRIGGER Mode Normal —
MEAS
* You may need to press Select Page to display this selection.
Recall Saved
Setup
OK Recall
Factory
Gating & High-Low
Setup
Select Measrmnt Ampl*
OK Select
Measrmnt
Recall Factory
Setup
—
High-Low Method Min/Max
—
—
—
2. Connect the TekScope instrument to the leveled sine wave generator as
shown below.
Leveled
sine wave
generator
Output
BNC cable
50 Ω feedthrough
terminator
Ch 1
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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 mV
p-p
so that the measured amplitude is approximately 500 mV. (The measured
amplitude can fluctuate around 500 mV.)
8. Press SET LEVEL TO 50%. Adjust TRIGGER LEVEL as necessary and
then check that triggering is stable.
9. Change the TekScope instrument setup using the following steps:
SCOPE TRIGGER Slope \ (falling edge)
10. Press SET LEVEL TO 50%. Adjust TRIGGER LEVEL as necessary and
then check that triggering is stable.
11. Change the TekScope instrument setup using the following steps:
SCOPE TRIGGER Slope / (rising edge)
12. Proceed to the next test to check the channel 2 edge trigger sensitivity.
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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.
Then, perform these additional steps to check the channel 2 edge trigger
sensitivity:
SCOPE
* You may need to press Select Page to display this selection.
CH 1
WAVEFORM
OFF
CH 2
TRIGGER Trigger Source Ch2
MEAS
— — —
Gating & High-Low
Setup
Select Measrmnt Ampl*
OK Select
Measrmnt
High-Low Method Min/Max
—
—
2. Connect the TekScope instrument to the leveled sine wave generator as
shown below.
Leveled
sine wave
generator
Output
BNC cable
50 Ω feedthrough
terminator
Ch 2
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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 mV
p-p
so that the measured amplitude is approximately 500 mV. (The measured
amplitude can fluctuate around 500 mV.)
6. Press SET LEVEL TO 50%. Adjust TRIGGER LEVEL as necessary and
then check that triggering is stable.
7. Change the TekScope instrument setup using the following steps:
SCOPE TRIGGER Slope \ (falling edge)
8. Press SET LEVEL TO 50%. Adjust TRIGGER LEVEL as necessary and
then check that triggering is stable.
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Performance Verification
Check Meter DC Voltage
Accuracy
This test checks the meter DC voltage accuracy.
1. Set the DC voltage source output level to 0V.
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.
DC voltage
source
+--
Banana cables
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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.
DC Voltage Source
Range
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
Output Level
Accuracy Limits
5. Set the DC voltage source output level to 0V.
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Performance Verification
Check Meter AC Voltage
Accuracy
This test checks the meter AC voltage accuracy.
1. Set the AC voltage source output level to 0V.
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.
AC voltage
source
Banana cables
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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.
AC Voltage Source
Range
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
Output Level
Accuracy Limits
6. Set the AC voltage source output level to 0V.
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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 — Ω —
2. Connect the TekScope instrument to the resistance standard as shown below.
Resistance
standard
Banana cables
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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.
Resistance Standard
Range
400 Ω 360 Ω 358.0 Ω to 362.0 Ω
4kΩ 3.6 kΩ 3.580 kΩ to 3.620 kΩ
40 kΩ 6kΩ 5.95 kΩ to 6.05 kΩ
40 kΩ 36 kΩ 35.80 kΩ to 36.20 kΩ
400 kΩ 360 kΩ 358.0 kΩ to 362.0 kΩ
4MΩ 3.6 MΩ 3.580 MΩ to 3.620 MΩ
40 MΩ* 36 MΩ* 35.23 MΩ to 36.77 MΩ
* These limits apply only when the relative humidity is ≤ 60%.
Setting
Accuracy Limits
This completes the performance verification procedure.
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Performance Verification
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Adjustment Procedures
C
alibra
tionOption(Op
tio
CalibrationOption(Optio
n
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. Before performing any procedure in this chapter, first verify that the instrument does not meet specifications.
Refer to the chapter Performance Verification for procedures to verify the
specifications.
Required Equipment
The following equipment, or a suitable equivalent, is required to complete these
procedures.
Minimum
Description
DC Voltage Source 400 mV to 800 V, ±0.1%
AC Voltage Source 400 mV to 600 V, ±0.5%
Resistance Standard 100 Ω to 10 MΩ, ±0.1%
Fast-Rise Square Wave
Generator
Banana to Banana Cable (two
required)
50 Ω BNC Cable BNCmaletoBNCmale,
50 Ω BNC Cable BNCmaletoBNCmale,
Requirements
accuracy
accuracy at 500 Hz
accuracy
300 mV step, ≤20 ns risetime,
≤0.5% flattness from 500 ns
to 200 s, 500 Hz or 950 Hz,
nominal 50% duty cycle
Shielded banana jacks on
each end
≈ 36 in (1 m) long
≈ 10 in (25 cm) long
Examples
Wavetek 9100 Universal
Calibration System with Oscilloscope Calibration Module
(Option 250)
Fluke 5500AMulti-product
Calibrator with Oscilloscope
n
5500A-SC)
Tektronix Deluxe Meter Lead
Set (ATLDX1)
Tektronix part number
012-0482-00
Tektronix part number
012-0208-00
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Adjustment Procedures
Minimum
Description Examples
50 Ω Feedthrough
Termination
Dual Banana to BNC Adapter Banana plugs to BNC female Tektronix part number
Requirements
BNC male and female connectors
Tektronix part number
011-0049-01
103-0090-XX
BNC T One male and two female
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. After adjustment is complete,
the jumper should be replaced to protect the calibration of the instrument.
Oscilloscope adjustment and meter adjustment are independent procedures. You
can choose to adjust either or both. Each procedure consists of a series of steps;
as you move through these steps, the TekScope instrument display provides
instructions that describe the specific input signal requirements for each step.
NOTE. During some steps, the instrument may appear to be idle for several
minutes while it is processing information internally. Please have patience.
If all steps in the procedure are completed successfully, a “Pass” message is
displayed and the new calibration constants take affect. If any step fails, the
procedure is aborted and the current calibration is not affected. You can also
choose to abort the procedure at any step.
BNC connectors
Tektronix part number
103-0030-XX
52
Before performing adjustment procedures, you must warm up the instrument at
least ten minutes in an ambient temperature between 20° C and 30° C. Adjustments performed prior to warm-up or outside this temperature range may result
in poor performance.
In this manual, TekScope instrument setups are shown in tables. Refer to
Conventions on page x for information about how to use these tables.
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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. Also, to prevent possible injury to service personnel or damage to
electrical components, read Preventing ESD on page 63.
Use this procedure to access and remove the adjustment-lockout jumper.
1. Disconnect all probes, cables, or meter leads from the instrument.
2. Disconnect the AC adapter, open the battery door, and remove the battery.
3. Place the TekScope instrument face down on a soft surface (such as an
anti-static mat).
Adjustment Procedures
4. Use the torque-limiting Torx® T-15 screwdriver to remove the four screws
that hold the case together.
5. Holding the case together, pick it up and place it back side down on a soft
surface.
6. As you lift the front cover off the instrument, press the buttons as necessary
to prevent the switch mat from coming off with the front cover.
7. To remove the switch mat, lift it off the switch flex-circuit assembly. Place it
button-side down on a clean surface.
CAUTION. To avoid contamination of switch contacts, do not touch the carbon
contacts on the switch flex-circuit assembly or on the back side of the switch
mat.
8. Fold the switch flex-circuit assembly toward you to expose the display
module, inverter board, and adjustment-lockout jumper. The jumper location
is shown in Figure 7.
9. Use the needle nose pliers to remove the adjustment-lockout jumper from the
instrument. Set the jumper aside for replacement after the adjustment is
complete.
10. To reassemble the instrument, fold the switch flex-circuit assembly back
over the display module and inverter board.
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Adjustment Procedures
Adjustment-lockout
jumper
Figure 7: 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. Holding the case together, pick it up and place it front side down on a soft
surface.
CAUTION. To avoid cross-threading or cutting new threads with the screws,
carefully follow the procedure in the next step.
14. 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.
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15. Replace the battery as shown on page 16, and then close the battery door.
Oscilloscope Adjustment
Three equipment setups, shown in Figure 8, 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 4 summarizes the steps
in the procedure and the signal requirement for each step.
Table 4: Summary of oscilloscope adjustment steps
Step Uses Equipment Setup Signal Source Setting
1 Square wave generator setup Fast rise output, 300 mV
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).
amplitude,
500 Hz or 950 Hz frequency
p-p
2 Zero voltage setup None
5 DC voltage setup +7.000 V
6 DC voltage setup --7.000 V
7 DC voltage setup +700.0 mV
8 DC voltage setup --700.0 mV
9 DC voltage setup +70.00 mV
10 DC voltage setup --70.00 mV
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Adjustment Procedures
Square wave generator setup
Fast rise square
wave generator
Output
36 inch BNC cable
Zero voltage setup
BNC ‘T’ connector
BNC ‘T’ connector
10 inch BNC cable
Ch 1
10 inch BNC cable
Ch 1
50 Ω feedthrough
terminator
Ch 2
50 Ω feedthrough
terminator
Ch 2
56
DC voltage setup
DC voltage
source
BNC ‘T’ connector
+--
Dual banana
to bnc adapter
36 inch BNC cable
Figure 8: Oscilloscope adjustment setups
THS710A, THS720A, THS730A & THS720P Service Manual
10 inch BNC cable
Ch 1
Ch 2
Page 71
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 8.
3. Set the fast rise square wave generator to produce an amplitude between
250 mV
and 300 mV
p-p
, and frequency between 450 Hz and 950 Hz
p-p
(inclusive).
4. Use the TekScope instrument setup below to start the oscilloscope adjustment process. For each step, follow the specific instructions displayed by the
instrument to connect the correct signal source and then confirm that you are
ready to proceed to the next step.
SCOPE UTILITY
System Cal
Factory Scope
OK Factory Cal Scope
—
Completing the
Adjustment Process
NOTE. During some steps, the instrument may appear to be idle for several
minutes while it is processing information internally. Please have patience.
If any step in the procedure fails, the procedure terminates. Failure will result if
an incorrect signal source is connected. If this happens, you must start the
procedure over from the beginning.
If the procedure completes successfully, a “Pass” message is displayed and the
new adjustment takes effect.
After adjusting the oscilloscope, continue with one of the following steps:
H Proceed to Meter Adjustment on page 58 to adjust the meter voltage
references.
H Proceed to Replacing the Adjustment-Lockout Jumper on page 61 to protect
the instrument from inadvertent readjustment.
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Adjustment Procedures
Meter Adjustment
Three equipment setups, shown in Figure 9, 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 summarizes the steps
in the procedure and the signal requirement for each step.
Table 5: Summary of meter adjustment steps
Step Uses Equipment Setup Signal or Resistance Source Setting
1 DC voltage setup +400.0 mV
2 DC voltage setup 4.000 V
3 DC voltage setup 40.00 V
4 DC voltage setup 400.0 V
5 DC voltage setup 850.0 V
6 AC voltage setup 400.0 mV
7 AC voltage setup 4.000 V
8 AC voltage setup 40.00 V
9 AC voltage setup 400.0 V
10 AC voltage setup 600.0 V
RMS
RMS
RMS
RMS
RMS
, 500 Hz
, 500 Hz
, 500 Hz
, 500 Hz
, 500 Hz
11 Resistance standard setup 100.0 Ω
12 Resistance standard setup 1.000 kΩ
13 Resistance standard setup 10.00 kΩ
14 Resistance standard setup 100.0 kΩ
15 Resistance standard setup 1.000 MΩ
16 Resistance standard setup 10.00 MΩ
17 DC voltage setup
18 DC voltage setup
1
In steps 17 and 18, the DC voltage source must be able to sink approximately 1 mA
1
1
500.0 mV
1.000 V
supplied by the TekScope instrument. You must determine whether or not your DC
voltage source is capable of sinking current supplied by a device under test. If the
DC voltage source cannot sink current, you can connect a 470 Ω,
1
?8W shunt
resistor across the output of the DC voltage source during steps 17 and 18 only. The
shunt resistor will accommodate the current supplied by the TekScope instrument.
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DC voltage setup
AC voltage setup
Adjustment Procedures
DC voltage
source
+--
Banana cables
AC voltage
source
Banana cables
Resistance standard setup
Banana cables
Figure 9: Meter adjustment setups
Resistance
standard
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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 9.
3. Set the DC voltage source amplitude to 400 mV.
4. Use the TekScope instrument setup below to start the meter adjustment
process. For each step, follow the specific instructions displayed by the
instrument to connect the correct signal source and confirm that you are
ready to proceed to the next step.
METER UTILITY
System Cal
Factory DMM
OK Factory Cal DMM
—
If any step in the procedure fails, the procedure terminates. Failure will result if
an incorrect signal source is connected. If this happens, you must start the
procedure over from the beginning.
Completing the
Adjustment Process
If the procedure completes successfully, a “Pass” message is displayed and the
new adjustment takes effect.
After adjusting the meter, continue with one of the following steps:
H Return to Oscilloscope Adjustment on page 55 to adjust the oscilloscope
voltage references.
H Proceed to Replacing the Adjustment-Lockout Jumper on page 61 to protect
the instrument from inadvertent readjustment.
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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 53.
However, in place of step 9, reinstall the jumper onto pins 1 and 2 as shown in
Figure 10.
Adjustment Procedures
Adjustment-lockout
jumper position
Figure 10: Relocating the adjustment-lockout jumper
This completes the adjustment procedure.
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Adjustment Procedures
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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.
H Removal and Installation Procedures provide procedures for the removal and
installation of modules.
H Troubleshooting provides information for isolating failed modules.
H Unpacking and Repacking Instructions provides packaging information for
shipment or storage.
Preparation
Preventing ESD
Only qualified personnel should perform service procedures. Read the 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.
When performing any service which requires internal access to the TekScope
instrument, adhere to the following precautions to avoid damaging internal
modules and their components due to electrostatic discharge (ESD).
CAUTION. Static discharge can damage any semiconductor component in this
instrument.
1. Minimize handling of static-sensitive modules.
2. Transport and store static-sensitive modules in their static protected
containers or on a metal rail. Label any package that contains static-sensitive
modules.
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Maintenance
3. Discharge the static voltage from your body by wearing a grounded antistatic
4. Nothing capable of generating or holding a static charge should be allowed
5. Handle circuit boards by the edges when possible.
6. Do not slide the modules over any surface.
7. Avoid handling modules in areas that have a floor or work-surface covering
Inspection and Cleaning
This section describes how to inspect for dirt and damage, and how to clean the
TekScope instrument. Inspection and cleaning are done as preventive maintenance. Preventive maintenance, when done regularly, may prevent malfunctions
and enhance reliability.
wrist strap while handling these modules. Do service of static-sensitive
modules only at a static-free work station.
on the work station surface.
capable of generating a static charge.
General Care
Inspection and Cleaning
Procedures
Preventive maintenance consists of visually inspecting and cleaning the
TekScope instrument, and using general care when operating it. How often to do
maintenance depends on the severity of the environment in which the instrument
is used. A proper time to perform preventive maintenance is just before
adjustment of the instrument.
Protect the TekScope instrument from adverse weather conditions. The instrument is not waterproof.
Do not store or leave the instrument where the LCD display will be exposed to
direct sunlight for long periods of time.
The front and back covers help keep dust out of the TekScope instrument and
must be in place during normal operation.
CAUTION. To avoid damage to the TekScope instrument, do not expose it to any
sprays, liquids, or solvents.
Inspect and clean the TekScope instrument as often as operating conditions
require. The collection of dirt on internal components can cause them to overheat
and breakdown. Dirt acts as an insulating blanket, preventing efficient heat
dissipation. Dirt also provides an electrical conduction path that could cause an
instrument failure, especially under high-humidity conditions.
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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. Remove loose dust on the outside of the instrument with a lint free cloth.
Use care to avoid scratching the clear plastic display filter.
2. Use a soft cloth or paper towel dampened with water to clean the instrument.
You can use a 75% isopropyl alcohol solution for more efficient cleaning.
CAUTION. To avoid damage to the surface of the TekScope instrument, do not use
any abrasive or chemical cleaning agents.
Inspection — Interior. During normal use, the TekScope instrument case seals the
internal components against common dust and dirt. However, if it appears that
the instrument may have been damaged or has been exposed to an unusually
dirty or wet environment, you should inspect and clean the interior.
To inspect and clean the interior, disassemble the instrument according to the
procedure Complete Disassembly on page 85.
Inspect the internal portions of the instrument for damage and wear using Table 6
as a guide. Defects found should be repaired immediately.
Table 6: Internal inspection check list
Item Inspect For Repair Action
Front and Back
Cover
Hole Plugs, Gasket
and Foam Pads
Circuit boards Loose, broken, or corroded solder
Cracks or deformations. Scratched
lettering or display filter. Loose
connectors or labels.
Misplaced or missing pieces. Relocate or replace defective
connections. Burned circuit
boards. Burned, broken, or
cracked circuit-run plating.
Repair or replace defective hardware.
pieces.
Remove failed module and replace
with a new module.
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Maintenance
Table 6: Internal inspection check list (Cont.)
Item Repair ActionInspect For
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. Blow off dust with dry, low-pressure, deionized air (approximately 9 psi).
2. Remove any remaining dust with a lint-free cloth dampened in isopropyl
alcohol (75% solution) and rinse with warm deionized water. (A cottontipped applicator is useful for cleaning in narrow spaces and on circuit
boards.)
STOP. If, after performing steps 1 and 2, a module is clean upon inspection, skip
steps 3 and 4. Proceed with step 5.
If steps 1 and 2 do not remove all the dust or dirt, all modules in the instrument
except the Display Module may be spray washed using a solution of 75%
isopropyl alcohol. Proceed with step 3.
3. Spray wash dirty parts with the 75% isopropyl alcohol solution and wait
60 seconds for the majority of the alcohol to evaporate.
66
4. Use hot (49_ Cto60_ C / 120_ F to 140_ F) deionized water to thoroughly
rinse the parts.
5. Dry all parts with low-pressure, deionized air.
6. Dry all components and assemblies in an oven or drying compartment using
low-temperature (52_ Cto66_ C / 125_ F to 150_ F) circulating air.
Lubrication. There is no periodic lubrication required for the TekScope instrument.
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Removal and Installation Procedures
This section describes how to remove and install the major mechanical and
electrical modules. It provides the following information:
H List of Modules on page 67 describes where to locate a list of replaceable
modules.
H Summary of Procedures on page 68 lists the procedures for removal and
installation of modules.
H Tools Required on page 69 describes the tools needed to perform the
procedures.
H Tilt Stand, on page 70, begins a series of procedures that describe the
removal and installation of modules.
Maintenance
Preparation
List of Modules
Please read the following warning statement. Then read the following general
instructions before removing a module.
WARNING. Only qualified personnel should perform service procedures. 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 63.
1. Read the Summary of Procedures on page 68 to understand which procedure
to use to access a given module. Then read Tools Required on page 69 for a
list of tools needed to remove and install modules in the TekScope instrument.
2. If you are disassembling the TekScope instrument for cleaning, refer to the
Inspection and Cleaning procedure on page 64 for cleaning instructions.
The Mechanical Parts List chapter provides a list of all replaceable modules.
Any electrical or mechanical module, assembly, or part listed in the parts list is
referred to as a module.
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Maintenance
Summary of Procedures
Table 7 lists the removal and installation procedures in order of increasing
complexity.
Table 7: Removal and installation procedures
Procedure Modules Accessed Begins on Page
Tilt Stand Tilt stand 70
Front-Panel Label Front-panel label 72
Front Cover Front cover
Display shield
Switch mat
Gasket
Handle
Battery door
Screws
Display Module Display module
Inverter board
Back Cover DC power hole plug
73
78
81
I/O port hole plug
Back cover / back label / battery contact
assembly
Complete Disassembly Chassis / BNC connectors / banana jacks
Main board
Switch flex-circuit assembly
Display cable
Inverter board cable
Foam pad set
2
Some pieces in the foam pad set are accessed by the Front Cover and Back Cover
procedures.
2
85
68
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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 (1.3 N ⋅ m) range with Torx® T-15 tip
1
H Screwdriver with
@4inch flat blade
H Screwdriver with1@8inch flat blade
H Needle-nose pliers
H Sharp knife (X-ACTO® knife or equivalent)
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Maintenance
Tilt Stand
You will need a
1
@4inch 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).
1
2. Insert the
@4inch flat-bladed screwdriver into the gap between the tilt stand
and instrument case as shown in Figure 11.
3. Twist the screwdriver gently to release one side of the tilt stand from the
instrument case. Take care not to damage the case.
70
Figure 11: Removing the tilt stand
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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 12.
3. Rotate the tilt stand to slide the second hinge pin upward and into its socket.
1
Insert hinge pin into the socket.
2
Rotate the tilt stand to slide the
second hinge pin into its socket.
Figure 12: Installing the tilt stand
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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. Use this procedure to install a new front-panel label in either a new
or the existing front cover.
1. Peel the paper off the back side of the new label.
2. Handling the label by its edges only, align it with the recess in the front
cover as shown in Figure 13.
3. When properly aligned, press the new label into place.
Front-panel label
Recess in the front cover
Figure 13: Installing a new front-panel label
72
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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. Disconnect all probes, cables, or meter leads from the instrument.
2. Disconnect the AC adapter, open the battery door, and remove the battery.
3. Place the TekScope instrument face down on a soft surface (such as an
anti-static mat).
4. Use the Torx® T-15 screwdriver to remove the four screws that hold the case
together.
5. Holding the case together, pick it up and place it back side down on a soft
surface.
6. As you lift the front cover off the instrument, press the buttons as necessary
to prevent the switch mat from coming off with the front cover.
7. To remove the handle, slip it off its guides.
8. To remove the switch mat, lift it off the switch flex-circuit assembly. Place it
button-side down on a clean surface.
CAUTION. To avoid contamination of switch contacts, do not touch the carbon
contacts on the switch flex-circuit assembly or on the back side of the switch
mat.
9. To remove the battery door, use the needle-nose pliers to slip the retaining
tether off of the post inside the instrument case as shown in Figure 14.
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Maintenance
Figure 14: 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. Place the TekScope instrument back side down on a soft surface (such as an
anti-static mat).
2. To install the battery door, pass the retaining tether through the battery
opening from the outside and then use the needle-nose pliers to slip the
retaining strap onto the post (see Figure 14).
3. 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.
74
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Maintenance
4. If you are installing a new front cover, follow these steps to assemble it
before installation. Refer to Figure 15.
a. Install a new label using the procedure on page 72.
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. Install new foam pad as shown in Figure 15.
Display shield
Foam pad
Figure 15: Assembling a new front cover
d. Install a new gasket into the groove around the edge of the front cover.
As shown in Figure 16, start the gasket at the bottom of the cover
1
leaving a short (
@8inch) tail through the slot. Carefully press the gasket
into place around the rim with the
finish the installation, overlap the starting point and then pass the end of
the gasket through the remaining slot. Trim the ending tail to
length with the sharp knife.
THS710A, THS720A, THS730A & THS720P Service Manual
Front cover
1
@8inch flat-bladed screwdriver . T o
1
@8inch
75
Page 90
Maintenance
Gasket material
Front cover
Trim tails to
Overlap gasket material
1
@
inch
8
Figure 16: Installing the gasket
5. Slip the handle into the guides of the back cover as shown in Figure 17.
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.
76
7. Holding the case together, pick it up and place it front side down on a soft
surface.
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Velcro strip
Maintenance
Fold end of handle over
Figure 17: Installing the handle
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Maintenance
Display Module
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. 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 (12 in ⋅ lbs or 1.m N ⋅ m
maximum torque).
9. Replace the battery as shown on page 16, and then close the battery door.
1
You will need a
@8inch flat-bladed screwdriver to remove the display module
and inverter board.
Removal. First remove the front cover and switch mat using the procedure on
page 73. Then, use the following procedure to remove the display module and
inverter board.
1. Fold the switch flex-circuit assembly toward you to expose the display
module and inverter board.
CAUTION. To avoid scratching the surface of the display module, do not let it
touch any hard object.
The display module surface may scratch easily. To clean it, first try pressurized
air. If a soft cloth is required to clean it, use very light pressure.
2. To remove the inverter board, unplug the input and output connectors and
then lift the inverter board off the two guideposts. You may want to use the
1
@8inch flat-bladed screwdriver to help release the connectors from their
sockets.
3. To remove the display module, follow these steps:
a. Disconnect the cable from the display module to the inverter board, if it
is not already disconnected.
78
b. Lift the right side of the display module out of the chassis and fold the
display module to the left, as shown in Figure 18.
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Display cable connector
Maintenance
Display module
Inverter board
Spring
Switch flex-circuit board
Figure 18: Removing the display module
1
c. Using the
@8inch flat-bladed screwdriver, carefully open the display-
cable connector as shown in Figure 19.
d. When the connector is open, slip the display cable out of the connector
to free the display module.
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Maintenance
Contact side of cable
Figure 19: 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 18.
1
3. Insert the display cable into its connector and then use the
@8inch flat-bladed
screwdriver to close the connector. Check that the display cable is fully
inserted into the connector.
4. Fold the display module back into the chassis and seat it between the foam
pads.
5. Plug the cable from the display module into the inverter board and then route
the cable in the channels as shown in Figure 20.
6. Place the inverter board into its cavity over the guideposts in the chassis.
7. Reconnect the connector to the bottom of the inverter board and route the
wires as shown in Figure 20.
8. If you just installed a new display module, peel off the protective plastic
sheet.
9. Fold the switch flex-circuit assembly back over the display module and
inverter board.
80
10. Install the switch mat and front cover using the procedure on page 74.
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Inverter output
connector
Inverter board
Maintenance
Display module
Route cable
through channels
Back Cover
Inverter input
connector
Route cable
through channel
Route cable
under clip
Figure 20: Routing cables to the inverter board
You will need a
1
@8inch 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. If any of these parts are defective, the back cover must be replaced.
Removal. First remove the front cover and switch mat using the procedure on
page 73. Then, use the following procedure to remove the chassis assembly.
1. Place the instrument back-side down on a soft surface.
2. Lift the battery connector, located on the handle-side of the chassis, off its
retaining pins and disconnect the connector.
1
3. Insert the
@8inch flat-bladed screwdriver between the back cover and chassis
at the location shown in Figure 21.
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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 21: 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.
1
b. From the inside of the back cover, use the
@8inch flat-bladed screwdriver
to work each retaining tab out of its hole in the back cover.
Installation. Use this procedure to install the hole plugs and chassis assembly into
the back cover.
1. To install a new hole plug, insert the retaining tabs into their holes in the
back cover. While pushing on the plug from the outside, pull gently on the
tabs from the inside with the needle-nose pliers until they lock into place.
2. To install the chassis assembly into the back cover, follow these steps:
a. If the instrument was completely disassembled, check that the chassis is
properly assembled.
82
b. Check that all foam pads inside the back cover are correctly installed.
Refer to Figure 22 for the correct locations.
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Install DC power
hole plug
Maintenance
Install foam pads
Install foam pad
Install I/O port
hole plug
Install foam pad
Install foam pads
Figure 22: 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. Reconnect the battery wire connector and press it onto its retaining pins.
Check that the polarity of the connector is correct. Dress the wires into
the channel on the chassis as shown in Figure 23.
3. Install the switch mat and front cover using the procedure on page 74.
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Maintenance
Retain connectors
between pins
Locate ferrite
bead in cavity
Figure 23: Routing the battery wires
Dress wires from battery
pack through slots
84
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Complete Disassembly
Maintenance
1
You will need a
@8inch 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 73. Next, remove the chassis assembly using the procedure on page 81.
Then, use the following procedure to disassemble the chassis.
STOP. If you are disassembling only for cleaning, inspect the chassis assembly to
determine whether further disassembly is required to perform internal cleaning.
If so, then proceed.
1. Remove the display module and inverter board using the procedure on
page 78.
2. With the switch flex-circuit assembly folded toward you, place the chassis
assembly on a soft, static-free surface with the main board side facing up.
3. To remove the main board and switch flex-circuit assembly from the chassis,
follow these steps:
a. Use the needle-nose pliers to remove both coaxial connectors from the
back side of the BNC connectors. Be careful not to crush the cable.
1
b. Use the
@8inch flat-bladed screwdriver to open the display cable
connector on the main board and then disconnect the display cable. Refer
toFigure19onpage80ifnecessary.
c. Dress the battery cable outward to free it from obstructions.
d. Following the sequence (circled numbers) shown in Figure 24, lift gently
on the edges of the main board while releasing the board-retaining snaps.
CAUTION. To prevent damage to the flex circuit, take care not to twist the flex
circuit at its connection to the main board.
e. When all six snaps are released, lift the main board and switch flex-cir-
cuit assembly out of the chassis enough to access the back side of the
banana jacks.
f. Use the needle-nose pliers to remove both wires from the back side of
the banana jacks. Be careful not to deform the connectors attached to the
wires.
g. Complete the removal of the main board and switch flex-circuit
assembly and then place it on a soft, static-free surface with the two
metal shields facing up.
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Maintenance
Unplug connectors
Battery cable
Unplug connectors
4
3
1
2
Lift here
6
5
Display
module cable
Figure 24: Removing the main board and switch flex-circuit assembly
4. To remove the switch flex-circuit assembly from the main board, follow
these steps:
86
a. With the main board laying flat from the previous step, raise the switch
flex-circuit assembly to an upright position.
b. While holding the flex-circuit assembly upright, use both thumbs and
forefingers to grasp the left and right sides of the connector.
c. Carefully, alternate pulling on the left and right sides of the connector to
work it out of its socket. Do not pull one side out much farther than the
other or bent pins may result.
5. To remove the inverter board cable from the main board, unplug it.
NOTE. The BNC connectors and banana jacks are an integral part of the chassis.
If any of these connectors are defective, the chassis must be replaced.
THS710A, THS720A, THS730A & THS720P Service Manual
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