Tektronix TM 501 User manual

Tektronix, Inc.
P-.O. Box 500
Beaverton, Oregon
070-1304-01
Product Group 75
Tektronix-
COMMTTTHITO EXCCULENCE
TM 501
POWER MODULE
INSTRUCTION MANUAL
97077 Serial Number
First Printing MAY 1972
Revised JUN 1985

Copyright *1972, 1980 Tektronix, Inc. All rights reserved.
Contents o< this publication may not be reproduced in any
form without the written permission of Tektronix. Inc.
Products Of Tektromx. Inc and itssubsidiariesare covered
by U.S and foreign patents and/or pending patents.
TEKTRONIX. TEK. SCOPE-MOBILE, and
istered trademarks of Tektronix. Inc.
are reg-
Printed mUSA. Specification and price change privileges
are reserved.
INSTRUMENT SERIAL NUMBERS
Each instrument has aserial number on apanel insert, tag.
or stamped on the chassis. The first number or letter
designates the country of manufacture. The last five digits
of the serial number are assigned sequentially and are
unique to each instrument. Those manufactured in the
United States have six unique digits. The country of
manufacture is identified as follows;
BOOOOOO Tektronix. Inc., Beaverton. Oregon, USA
100000 Tektronix Guernsey, Ltd., Channel Islands
200000 Tektronix United Kingdom, Ltd., London
300000 Sony/Tektronix. Japan
700000 Tektronix Holland, NV, Heerenveen.
The Netherlands

TABLE OF CONTENTS TM 501
Page
OPERATORS SAFETY SUMMARY li
SERVICING SAFETY SUMMARY ill
Section 1SPECIFICATION
Introduction 1-1
Electrical Characteristics 1-1
Physical Characteristics 1-3
OPERATORS PART -ENGLISH
Section 2OPERATING INSTRUCTIONS
General 2-1
Building aSystem 2-1
Installation and Pre-Turn On
Procedure 2-3
Section 3MAINTENANCE
General 3-1
Troubleshooting Aids 3-1
Troubleshooting Techniques 3-2
Parts Ordering and Replacing .... 3-3
installation Procedure 3-8
Section 4OPTIONS
Option 24-1
Option 74-1
Section 5REPLACEABLE ELECTRICAL PARTS
Sections DIAGRAMS AND CIRCUIT BOARD
ILLUSTRATION
Section 7REPLACEABLE MECHANICAL PARTS
CHANGE INFORMATION
REVCJUL 1980 I

TM 501
OPERATORS SAFETY SUMMARY
Terms In This Manuel
CAUTION statements identify conditions or practicesthat
could result in damageto the equipment or other property.
WARNING statements identify conditions or practices
that could result in personal injury or loss of life.
Terms As Marked on Equipment
CAUTION indicates apersonal injury hazard not im-
mediately accessible as one reads the marking, or a
hazard to property including the equipment itself.
DANGER indicates apersonal injury hazard immediately
accessible as one reads the marking.
Symbols In This Manual
AThis symbol indicates where applicable
cautionary or other information is to be
found.
Symbols As Marked on Equipment
DANGER ~High voltage.
Protective ground (earth) terminal.
ATTENTION —refer to manual.
Power Source
This product Is intended to operate from apower source
that will not apply more than 250 volts rms between the
supply conductors or between either supply conductor
and ground. Aprotective ground connection by way of the
grounding conductor in the power cord Is essential for
safe operation.
Grounding the Product
This product is grounded through the grounding conduc-
tor of the power cord. To avoid electrical shock, plug the
power cord into aproperly wired receptacle b^ore
connecting to the product input or output terminals. A
protective ground connection by way of the grounding
conductor in the power cord is essential for safe opera-
tion.
Danger Arising From Loss of Ground
Upon loss of the protective-ground connection, all
accessible conductive parts (including knobs and con-
trols that may appear to be insulating) can render an
electric shock.
Use the Proper Power Cord
Use only the power cord and connector specified for your
product.
Use only apower cord that is in good condition.
For detailed information on power cords and connectors,
see maintenance section.
Refer cord and connector changes to qualified service
personnel.
Use the Proper Fuse
To avoid fire hazard, use only the fuse of correct type,
voltage rating and current rating as specified in the parts
list for your product.
Refer fuse replacement to qualified service personnel.
Do Not Operate in Explosive Atmospheres
To avoid explosion, do not operate this product in an
explosive atmosphere unless it has been specifically
certified for such operation.
Do Not Remove Covers or Panels
To avoid personal injury, do not remove the product
covers or panels. Do not operate the product without the
covers and panels proprerly installed.
Do Not Operate Without Covers (for TM 500 plug-
ins only)
To avoid personal injury, do not operate this product
without cov^s or panels installed. Do not apply power to
the plug-in via aplug-in extender.
ii @JUL 1980

SERVICE SAFETY SUMMARY
FOR QUALIFIED SERVICE PERSONNEL ONLY
Refer also lo the preceding Operators Safely Summary.
TM 501
Do Not Service Alone
Do not perform internal service or adjustment of this
product unless another person capable of rendering first
aid and resuscitation is present.
Use Care Whert Servicing With Power On
Dangerous voltages exist at several points in this product.
To avoid personal injury, do not touch exposed connec-
tions and components white power is on.
Disconnect power before removing protective panels,
soldering, or replacing components.
Power Source
This product is intended to operate from apower source
that will not apply more than 250 volts rms between the
supply conductors or between either supply conductor
and ground. Aprotective ground connection by way of the
grounding conductor in the power cord is essential for
safe operation.
@JUL 1960 iii

.ignitf

Section 1<TM SOI
SPECIFICATION
INTRODUCTION
Description
The TM sot is asingle compartment module compati-
ble with all TM 500 plug-ins. It provides unregulated dc
and ac supplies and non-dedicated power transistors for
plug-ln usage. Option 2 rear interface allows Interconnec-
tion of special features with external devices through the
back panel.
Perfonnance Conditions
The values listed below are valid only when the instru-
ment is operated at an ambient temperature between O’C
and 50*C.
Table 1-1
ELECTRICAL CHARACTERISTICS
1
Characteristics Performance Requirements Supplemental Information
SUPPLIES
+33.5 Vdc '
Tolerance* +23.7 Vto +40.0 V
PARD (Periodic and Random
Deviation) <2.5 Vpp
Maximum load 350 mA
Maximum load di/dt 10 mA/ps
-33.5 Vdc
Tolerance* -23.7 Vto -40.0 V
PARD <2.5 Vpp
Maximum load 350 mA
Maximum load di/dt 10 mA/fJs
+11.5 Vdc
Tolerance* +7.6 Vto +16.0 V
PARD <2.5 Vpp
Maximum load 1.3 A
Maximum load di/dt 20 mA/ps
25 Vac (2 each)
Range 25.0 Vrms +10%. -15% floating
Maximum load 25 VAC
Maximum floating voltage 350 Vpeak
@JUL 1980 1-1

Spedfic«tion—TM 501
Table 1-1 (cont)
Characterlallcs Performance Requirements Supplemental Information
17.5 Vac‘
Range With agrounded center tap 20.5 Vrms
+10%. -20%
Maximum load 30 VA
Maximum plug-ln power drawn from
mainframe*
35 Wdc or 75 VAac
Combined power drawn sharing
limitation'
VAac +2.1 (Wdc) <VAac
Fuse data
+33.5 Vdc 2.5 A. 3AG, fast blow
-33.5 Vdc 2.5 A. 3AG. fast blow
+11.5 Vdc 7.5 A. 3AG, fast blow
SERIES PASS TRANSISTORS
Type One each NPN or PNP
Maximum dissipation 7.5 Weach. 15 Wtotal
SOURCE POWER REQUIREMENTS
Voltage ranges Selectable 100 V, 110 V. 120 V, 200 V.
220 V. and 240 Vnominal line ±10%
Line frequency 48 Hz to 440 Hz
Max power consumption 'Approximately 120 W
Fuse data
100 V. 110 V, 120 Vranges
^
0.6A slow blow
200 V. 220 V, 240 Vranges
I
0.3A med blow
MISCELLANEOUS
Maximum recommended plug-in power 10 to 15 W
dissipation
'Worst case; low line-full load and Mgh llne-no load values Irtdudlng PARD.
‘At nominal line voltage.
1-2 REV JAN 1983

specification—TM SOI
Table 1-2
PHYSICAL CHARACTERISTICS
Cfiaracteristics Supplemental Information
ENVIRONMENTAL'
Overall Meets or exceeds MIL-T-28800B. class 5requirements with exception for
vibration, shock, and EMC.
Temperature
Operati r>g 0*Cto -f-SO'C
Non-operating -40“Cto +7S*C
Humidity 90-95% RH for 5days cycled to -l-50*C.
Altitude
Operating 4.6 km (15.000 H)
Non-operating 15 km (50.000 ft)
Vibration 0.26 mm (0.010"), 10 Hz to 55 Hz. 75 minutes.
Shock 20 g's (1/2 sine). 11 ms, 18 shocks
Bench handling 45°. 4". or equilibrium whichever occurs first
Transportation Qualified under National Safe Transit Association Preshipment Test
Procedures 1A-B-1 and 1A-B-2.
MECHANICAL
Net weight 6.0 lbs (4.3 kg)
Overall dimensions 6.0 in (15.2 cm)H.3.9 in (9.9 cm)W, 15.3 in (38.9 cm)L
‘With plug-lns. Some plus-li^ require addlllonal limitations.
MtTtttC £OUIV*LtHCt
OCC'MU iM tfoc at* *io 450
A4f TRIC ijim) M/ C5 UA
REV AU0 1981 1-3

Section 2—TM 501
OPERATING INSTRUCTIONS
GENERAL
liMtallation
For full installation instructions refer to the procedure
at the end of this section.
Power Source
The TM S01 is designed to operate from apower source
with its neutral at or near earth (ground) potential with a
separate safety-earth conductor. It is not Intended for
operation from two phases of amulti-phase system.
Power Usage
The TM 501 may require up to 30 watts at the upper
limits of high line voltage ranges. Actual power consump-
tion depends on the particular plug-in and operating mode
selected.
Loading Considerations. The power capability of the
TM 501 can best be used by carefully planningthe plug-in
configuration, the external loads, and the resulting power
distributions. Optimum conditions may be obtained by:
1. Dissipating as much power as possible In the
external loads.
2. Operating the system in an ambient temperature
near 25® C.
The plug-in is provided access to apair of heat-sinked,
series-pass transistors, one NPN and the other PNP.
These transistors enable the plug-in to operate in power
ranges not possible If the power were to be dissipated in
the plug-in.
Operating Temperatures
The TM 501 can be operated in an ambient air
temperature of 0®C to 50“C.
Since the TM SOJ can be stored in temperatures
between -40®C and +75®C, allow the instrument's
chassis to return to within the operating limits before
applying power.
Module Installation
Turn fhe PowerModule off before inserting the plug-
in; otherwise damage may occur to the plug-in
circuitry.
1. Check the location of the white plastic barrier keys
on the TM 501 interconnecting jack to ensure that their
locations match the slots in the edge of the plug-in
module's circuit board.
2. Align the plug-in module chassis with the upper and
lower guides of the selected compartment. Push the
module in and press firmly to seat the circuit board in the
interconnecting jack. (Remove the plug-in module by
pulling on the white release latch in the lower left corner of
each module.)
Turn-on Procedure
After completing the Installation procedure, found at
the end of this section, and installing the plug-in, pull the
POWER switch on the right side of the TM 501. Some
plug-ins have Independent power switches, usually
labeled OUTPUT, controlling application of mainframe
power to the plug-in. Press this button to activate the plug-
in.
BUILDING ASYSTEM
Family Compatibility
Mechanically, the plug-in modules are very similar to
other Tektronix product families. However, they are not
electrically compatible. Therefore, the TM 501 interface
has barriers on the mating connectors between pins 6and
7to ensure that incompatible modules cannot be inserted.
See Fig. 2-1. Acompatible module will have amatching
slot between pins 6and 7of its main circuit board edge
connector. This slot and barrier combination is the
primary keying assignment.
TM 500-compatibie plug-in modules are also Identified
by the white color of the release latch.
@JUL 1980 2-1

Operating Instructions—TM 501
Fig. 2>1. Keying assignments lor lamlly functions. One ot many possible sequence combinalions.
Customizing the Interface
The modularity of this instrumentat ion system provides
for many different functions to be performed by the plug-
in modules. Specific functions are grouped into families or
classes, of which there may be several plug-in module
members. For instance, some classes are Power Supplies.
Signal Sources. Measurement, and soforth. Each modular
member of afunctional family will have asecond slot
peculiar to its family assignment located in its edge
connector The TM 501 user can "program "the Power
Module to accept only members of that family by installing
asecond barrier in the interface connector to match the
module's slot location. For extra barriers, order Tektronix
Part No. 214-1593-02.
Jumper wires can be used to further specialize the
interface. Compartments can be made to "talk" to each
other by connecting jumpers on the back side of the
interface board, using pins 14 through 28 (A-side and B-
side both) of the interconnecting jacks See the following
description of Option 2. Refer to each plug-in module's
Manual for the I/O assignments of each pin at the rear
interface. Once having made interconnections ot a
specialized nature, it is recommended that barriers be
Installed on the interconnecting jacks to ensure module
compatiblity with the customized wiring.
Rear Panel
The rear subpanel has aconnector mounting plate for
BNC and multi-pin connector mountings. Customer or
factory-installed connectors and wiring (see following
description of Option 2) could provide external access to
the interface for external I/O control. This feature makes
the TM 500 Series Modular Instrumentation System very
flexible in bench-top or rackmounted systems.
Option 2.This factory-installed option adds 25-mil
square-pin connectors to the rear of the interconnecting
jacks at all pin locations from pins 14A and Bthrough pins
28A and B. This will keep the interface flexible by making It
easy arKf fast to change customized wiring using prepared
wires with square-pin receptacles and long-nose pliers or
tweezers. It also protects the circuit board from damage by
repeated soldering ar>d unsoldering of jumper wires. This
option also adds one BNC connector and one 50-pin con-
nector to the rear panel. These connectors are not pre-
wired. Instead, prepared jumpers, coaxial cables, and
interconnection jack barriers are Included in akit. This gives
asystem designer as much flexibility as possible.
2-2 REV JAN 1983

Operating Instructions—TM 501
INSTALLATION AND PRE-TURN ON
PROCEDURE
Check the rear panel markings. If the factory settings
are compatible with the available line voltage and frequen-
cy, insert the desired plug-ins. If achange is needed, refer
aqualified service person to the procedure in the
Maintenance section of this manual.
@JUL 1960 2-3

Section 3-TM 501
MAINTENANCE
GENERAL
Introduction
This section of the manual is meant to support the
entire TM 500 Series family of modules with a general
coverage of the most commonly-needed service informa-
tion pertinent to preventive maintenance, trouble-
shooting. ordering parts, and replacing components and
sub-assemblies.
Preventive Maintenance
Preventive maintenance steps performed on aregular
basis will enhance the reliability of the instrumentation
systems. However, periodic checks of the semiconductors
in the absence of amalfunction are not recommended as
preventive maintenance measures. See the semiconduc-
tor checking information under Troubleshooting Techni-
ques which follow. Aconvenient time to perform preven-
tive maintenance is just before instrument calibration.
Cabinet Removal WARMfMG
Dangerous potentials exist at several points
throughout the system. When the system must be
operated with the cabinet removed, do not touch
exposed connections or components. Some tran-
sistors have vo/rage present on their cases.
Disconnect power before cleaning the system or
replacing parts.
Two screws secure the cabinet to the TM 501 frame.
Remove them and lift the cabinet straight up. Do not
operate the system with the cabinet removed any longer
than necessary for troubleshooting and calibration. Re-
install the cabinet to protect the interior from dust and to
remove personnel shock hazards.
Calibration
To ensure accurate signal generation and measure-
ment, the performance of individual units comprising the
system should be checked periodically. Refer to the
Instruction Manual for each unit for complete calibration
and verification procedures.
TROUBLESHOOTING AIDS
Introduction
The following is provided to augment Information
contained elsewhere in this and other TM 500 series
family manuals when troubleshooting becomes nec-
essary.
Avoid using chemical cleaning agents which might
damage plastic parts. Avoid chemicals containing
benzene, toluene, xylene, acetone, or similar
solvents.
Exterior. Loose dust may be removed with asoft cloth
or adry brush. Water and amild detergent may be used.
However, abrasive cleaners should not be used.
Interior. Cleaning the interior of aunit should precede
calibration since the cleaning processes could alter the
settings of calibration adjustments. Use low-velocity
compressed air to blow off accumulated dust. Hardened
dirt can be removed with asoft brush, cotton-tipped swab,
or acloth dampened in asolution of water and mild
detergent.
Circuit Description
Each manual has asection devoted to explaining circuit
operating theory. Used with the schematics, this can be a
powerful analytic toot.
Diagrams
Block diagrams and detailed circuit schematics are
located on foldout pages in the service section of most of
the TM 500 Series family manuals. The schematic
diagrams show the component values and assigned
circuit reference numbers of each pari necessary to the
circuit design. Usually the first page of the service section
defines the circuit symbols and reference designators
used in that particular instrument. Major circuits are
usually identifiable by a series of component numbers.
Important waveforms and voltages may be shown within
the diagrams or on adjoining aprons. Those portions of
the circuits located on circuit boards are enclosed with a
grey tint outline.
@JUN 1980 3-1

Maintenance—TM 501
Cam Switch Charts
Cam switches shown on the diagrams are coded on
charts to located the cam number of the switch contact in
the complete switch assembly, counting from the front, or
knob end, toward the rear of the switch. The charts also
indicate with a solid dot when each contact is closed.
Circuit Board Illustrations
Line illustrations showing component locations keyed
with agrid scheme for each circuit board are usually
placed on the back of afoldout page and sequenced as
close as possible to an associated schematic. The GRID
LOG columns, located near the Parts Location Grid, keys
each component to easy location on the board.
System and Associated Equipment
Before proceeding with troubleshooting the TM 500
Series system, check that the instruments in the system
are operating correctly. Check for proper interconr>ection
between the power module and the plug-in modules.
Check the li ne voltage at the power source. Check that the
signal is properly connected and that the interconnecting
cables and signal source are not defective.
The associated plug-in modules can be checked for
proper operation quickly by substituting other like units
known to be operating properly. If the trouble persists
after substitution, then the power module is probably at
fault. Moving aproperly operating plug-in from compart-
ment to compartment will help determine If one or more
compartments have aproblem.
Component and Wiring Color Codes
Colored stripes or dots on electrical components
signify electrical values, tolerances, etc., accordingto EIA
standards. Components not color-coded usually have
information printed on the body. The wiring coding
follows the same EIA standards with the exception of the
ac power cord of the PowerModules. It is coded like this;
Visual Check
Inspect the portion of the system In which the trouble is
suspected. Many troubles can be located by visual clues
such as unsoldered conrtections, broken wires, damaged
circuit board, damaged components, etc.
Power Cord Conductor Identification
Alternate Color
Black
White
Green-Yellow
Testirtg Equipment
Instrument Calibration
Check the calibration of the suspected plug-in module
or the affected circuit if thetrouble Is ob\4ously in acertain
circuit. The trouble may only be aresult of misadjustment
or may be corrected by re-calibration. Complete calibra-
tion instructions are given in the manual for each instru-
ment in the system.
Conductor Color
Ungrounded (Line)
Grounded (Neutral)
Grounding (Earthing)
Brown
Blue
Green-Yellow
Generally, awide-band oscilloscope, a probe, and a
multimeter are all that Is needed to perform basic
waveform and voltage checks for diagnostic purposes.
The calibration procedures in the manual for each plug-in
module list specific test equipment and the features
necessary to adequately check out that particular module.
Circuit isolation
Note the trouble symptoms. These often Identify the
circuit in which the trouble is located. When trouble
symptoms appear in more than one circuit, check the
affected circuits by making waveform and voltage
measurements.
TROUBLESHOOTING TECHNIQUES
Introduction
This troubleshooting procedure is arranged in an order
which checks the simple trouble possibilities before
proceeding to extensive troubleshooting.
Control Settings
Incorrect control settings can indicate atrouble that
does not exist. If there is any question about the correct
function or operation of any control, see the Operating
Instructions section of the manual for the instrument
involved.
Irworrect operation of all circuits often means trouble
in the power supplies. Using amultimeter, check first for
correct voltages of the individual regulated supplies
according to the plug-in module schematics and calibra-
tion procedures. Then check the unregulated supplies of
the power modules. Defective components elsewhere in
the instruments can appear as power supply problems. In
these instartces, suspected circuits should be dis-
connected from apparently bad power supplies one at a
time to narrow the search.
Voltages and Waveforms
Often defective components can be located by using
waveform and voltage indications when they appear on
3-2 @JUN 1980

Maintenance—TM 501
the schematic or in the calibration procedures. Such
waveforms and voltage labels are typical indications and
will vary between instruments. To obtain operating con-
ditions similar to those used to take these readings, refer
to the first diagram in the service sections.
Component Checking
If acomponent cannot be disconnected from its circuit,
then the effects of the associated circuitry must be
considered when evaluating the measurement. Except for
soldered-in transistors and integrated circuits, most com-
ponents can be lifted at one end from the circuit board.
Transistors and IC’s. Turn the power switch off before
removing or replacing any semiconductor.
Agood check of transistor operation is actual perfor-
mance under operating conditions. Atransistor can most
effectively be checked by substituting anew component
for it (or one which has been checked previously).
However, be sure that circuit conditions are not such that a
replacement transistor might also be damaged. If sub-
stitute transistors are not available, use adynamic tester.
Static-type testers are not recommended, since they do
not check operation under simulated operating con-
ditions. Asuction-type desoldering tool must be used to
remove soldered-in transistors: see component replace-
ment procedure for details.
Integrated circuits can be checked with a voltmeter,
test oscilloscope, or by direct substitution. Agood
understanding of the circuit description is essential to
troubleshooting circuits using IC's. Operating wave-
forms, logic levels, and other operating information for the
IC's are given in the circuit description information of the
appropriate manual. Use care when checking voltages
and waveforms around the IC's so that adjacent leads are
not shorted together. Aconvenient means of clipping a
test probe to the 14- and 16-pin irvline IC's is with an
integrated circuit test clip. This device also doubles as an
extraction tool.
Diodes. Do not use an ohmmeter that has ahigh
internal current. High currents may damage the diode.
Adiode may be checked for an open or shorted
condition by measuring the resistance between terminals.
With an ohmmeter scale having an internal source of
between 800 mV, and 3V. the resistance should be very
high in one direction and very low when the leads are
reversed
Resjstors. Check the resistors with an ohmmeter.
Resistor tolerances are given in the Electrical Parts List in
every manual. Resistors do not normally need to be
replaced unless the measured value varies widely from the
specified value.
Capacitors. Aleaky or shorted capacitor can be
detected by checking resistance with an ohmmeter on the
highest scale. Use an ohmmeter that will not exceed the
voltage rating of the capacitor. The resistance reading
should be high after initial charge of the capacitor. An
open capacitor can best be detected with acapacity meter,
or by checking whether it passes ac-signals.
PARTS ORDERING
AND REPLACING
Ordering
Obtaining Replacement Parts. Most electrical and
mechanical parts can be obtained through your local
Tektronix field office or representative. However, you
should be able to obtain many of the standard electronic
components from alocal commercial source in your area.
Before you purchase or order apart from asource other
than Tektronix Inc., please check the electrical parts list
for the proper value, rating, tolerance and description
Special Parts. Some parts are manufactured or
selected by Tektronix. Inc. to satisfy particular re-
quirements, or aremanufacturedfor Tektronix, Inc., to our
specifications. Most of the mechanical parts used in this
system have been manufactured by Tektronix, Inc. Order
all special parts directly from the local Tektronix Field
Office or representative.
Ordering Procedure. When ordering replacement
parts from Tektronix. Inc., please include the following
minimum information:
1.
Instrument Type (PS 501. SG 502. DC 501, etc.)
2.
Instrument Serial Number (For example, B010251)
3.
Adescription of the part (if electrical include the
circuit number)
4.
Tektronix part number.
Please do not return any instruments or parts before
receiving directions from Tektronix, Inc.
Alisting of Tektronix Field Offices. Service Center and
Representatives can be found in the Tektronix Product
Catalog and Supplements.
@JUL 1980 3-3

Maintenance—TM 501
Replacing
The exploded view drawings with the Mechanical Parts
List, located to the rear of most manuals, may be
especially helpful when disassembling or reassembling
individual components or sub-assemblies.
Circuit Boards. If acircuit board is damaged beyond
repair, either the entire assembly including all soldered-on
components, or the board only, can be replaced.
To remove or replace a board, proceed as follows;
1.
Disconnect all leads connected to the board (both
soldered lead connections and solderless pin connec-
tions).
2.
Remove all screws holding the board to the chassis
or other mounting surface. Some boards may be held
fast by plastic mounting clips around the board edges.
For these, push the mounting clips away from the
circuit board edges to free the board. Also, remove any
knobs, etc., that would prevent the board from being
lifted out of the instrument.
3.
Lift the circuit board out of the unit. Do not force or
bend the board.
4.
To replace the board, reverse the order of removal.
Use care when replacing pin connectors. If forced into
place incorrectly positioned, the pin connectors may
be damaged.
Transistors and IC's. Transistors and IC's should not
be replaced unless they are actually defective. If removed
from their sockets during routine maintenance, return
them to their original sockets. Unnecessary replacement
or switching of semiconductor devices may affect the
calibration of the instruments. When atransistor is
replaced, check the operation of the part of the instrument
that may be affected.
Replacement semiconductors should be of the original
type or adirect replacement. Figure 3-1 shows the lead
configurations of the semiconductors used in this instru-
ment system. When removing soldered-in transistors, use
asuction-type desoldering tool to remove the solder from
the holes in the circuit board.
Static-Sensitive Components
Static discharge cart damage arty semiconductor
component in this instrument.
This Instrument contains electrical components that
are susceptible to damage from static discharge. See
Table 3-1 for relative susceptibility of various classes of
semiconductors. Static voltages of 1kV to 30 kV are
common in unprotected environments.
Observe the following precautions to avoid damage:
1. Minimize handling of static-sensitive components
2.
Transport and store static-sensitive components or
assemblies in their original contairters, on ametal rail,
or on conductive foam. Label any package that con-
tains static-sensitive assemblies or components.
3.
Discharge the static voltage from your body by
wearing awrist strap while handling these components.
Servicing static-sensitive assemblies or components
should be performed only at astatic-free work station
by qualified service personnel.
4.
Nothing capableable of generating or holding a
static charge should be allowed on the work station
surface.
5.
Keep the component leads shorted together
whenever possible.
6. Pick upcomponenisbythebody, never by the leads.
7. Do not slide the components over any surface.
8.
Avoid handling components in areas that have a
floor or work surface covering capable of generating a
static charge.
9.
Use a soldering iron that is connected to earth
ground
3-4 @JUL 1960

Maintenance—TM S01
Fig. ^1. Semiconductor device lead configuration found in the TM 500 family.
10. Use only special antistatic suction type or wicK
type desoldering tools
Test Equipment
Before using any test equipment to make
measurements on static-sensitive components or
assemblies, be certainthat any voltage or current supplied
by the test equipment does not exceed the limits of the
component to be tested.
REV MAR 1982 3-5

Maintenance—TM 501
Table 3-1
RELATIVE SUSCEPTIBILITY TO
STATIC DISCHARGE DAMAGE
Semiconductor Classes
Relative
Susceptibility
Levels'
MOS or CMOS microcircuits or
discretes, or linear microcircuits
with MOS inputs (Most Sensitive) 1
ECL 2
Schottky signal diodes 3
Schottky TTL 14
High-frequency bipolar transistors 5
JFETs 6
Linear Microcircuits 17
Low-power Schottky TTL 8
TTL (Least Sensitive) 9
‘Vollage equivalent tor levels:
1100 to 500 V 4=S00V 7-400lo 1000V(est.)
2-200 to 500 V5400 to eOO V8=900 V
3-250 V6-600 to 800 V9~1200 V
(Voltage discharged from a100 pF capadlor through a
resistance of 100 ohms.)
Interconnecting Pins. To replace apin that is mounted
on acircuit board, first disconnect any pin connectors.
Then, unsolder the damaged pin and pull it out of the
board with apair of pliers. Be careful not to damage the
wiring on the board with too much heat. Ream out the hole
in the circuit board with a 0.031-inch drill. Remove the
ferrule from the new interconnecting pin and press the
new pin into the hole in the circuit board. Position the pin
in the same manner as the old pin and solder it in. If the old
pin was bent at an angle to mate with aconnector, bend
the new pin to match the associated pins.
NOTE
Apin replacement kit including necessary tools,
instructions, and rep/acemenf pins is available from
Tektronix. Inc. Order Tektronix Part No. 040-0542-
00.
Cam Switches. Repair of cam-type switches should be
undertake!^ only by experienced maintenance personnel.
Switch alignment and spring tension of the contacts must
be carefully maintained for proper operation of the switch.
For assistance, contact your local Tektronix Field Office
or representative.
NOTE
Acam-type switch repair kit including necessary
tools, instructions, and replacement contacts is
available from Tektronix. Inc. Order Tektronix Part
No. 040-0541-00.
The cam-type switches consist of rotating cam drums
which are turned by front-panel knobs, and sets of spring-
leaf contacts mounted on adjacent circuit boards. The
contacts are actuated by lobes on the cams. These
switches can be dissembled for inspection, cleaning,
repair, or replacement as follows:
1. Remove the screws which hold the metal cover on
the switch, and lift the cover off the switch. The switch is
now open for inspection or cleaning.
2. To completely remove aswitch from the circuit
board, first remove any knobs or shaft extensions. Loosen
the coupling at the potentionmeter at the rear of the
switch, and pull the long shaft out of the switch assembly.
3.
Remove the screws (from the opposite side of the
circuit board) that holds the cam drum to the board.
4.
To remove the cam drum from the front support
block, remove the retaining ringfrom the shaft onthefront
of the switch and slide the cam drum out of the support
block. Be careful not to lose the small detent roller.
5.
To replace defective switch contacts, follow the
instructions given in the switch repair kit.
€To re-install the switch assembly, reverse the above
procedure.
Pushbutton Switches. The pushbutton switches are
not repairable and should be replaced asaunitif defective.
Use asuction-type desoideringtool to remove solder from
the circuit board when removing these switches
Incandescent Bulbs. Most of these light bulbs are
mounted on the sub-panel using plastic sleeve stand-offs.
Unsolder the lead wires and pull the bulb out of the sleeve
from the rear of the sub-panel.
3-6 @JUL 1980

Maintenance—TM 501
Light-Emitting Diodes. LED's used as indicators are
mounted on the sub-panels with plastic sleeve sockets
similar to the Incandescent bulb mountings or they are
soldered directly to asub-assembly and so mounted that
they protrude through holes in the panel. In these cases,
the sub-assembly must be exposed and the anode and
cathode lead orientations carefully noted before un-
soldering the defective LEO. See Fig 3-2 for LED lead
Identifying information.
Power Transformer. Replace the transformer only
with aTektronix direct replacement transformer. Refer to
the exploded view drawing at the rear of the Power Module
manuals for disassembly of the rear panel to expose the
power transformer. Refer to the schematic diagram color-
coding information for correct wiring. After replacement
check out the power supply voltages before installing a
plug-in module.
Option 2
This factory installed option adds 25-mil square pin con-
nectors to the rear of the interconnecting jacks at all pin
locations from pins 14A and B. This will keep the interface
flexible by making it easy and fast to change customized
wiring using prepared wires with square pin receptacles. It
also protects the circuit board from damage by repeating
soldering and unsoldering of jumper wires. This option also
adds one BNC connector and one 50-pin connector to the
rear panel. These connectors are not prewired in order to
give asystem designer as much flexibility as possible. In-
stead. prepared jumpers, coax cables, arx] interconnection
jack barriers are included in the TM 501
.
System Design Directions.
1.
Plan the plug-in location based on the front-panel
controls and operator convenience as well as interface
connections.
2.
Plan the wiring between interconnecting jacks and to
the rear panel connectors carefully before starting
assembly. Amating rear panel 50-pin connector and cover
are provided for external cabling.
NOTE
There are no pin assignments for the rear panel
connectors, due to the great variety ol possible
connections.
When high frequency or fast digital signals are
involved, plan the wires so as to minimize crossstalk.
Make allowance for the possible need to make
auxiliary ground connecf/ons.
The 50’pin rear panel connector may be easier to
connect if it is removed from the rear panel and
remounted after connections are made. Remove the
top rear caPrnef piece for ease of access.
If more than SO pins are needed, an AMP HD-22
series connector with 104 pins may be mounted in
the same cut out. It is suggested that these parts be
obtained directly from AMP Inc., Harrisburg, PA or
their distributors. For further application informa-
tion. contact Tektronix' TM 500 Marketing Group,
Seaverfon. OR.
3. Pinassignmentsforindividual plug-inswill befound
in the appropriate instruction manual.
4. Install an interconnection jack barrier at the ap-
propriate location on the interconnection jack. Refer back
to operating instructions for keying assignments for
family functions
S. Select and install the wires (hook-up or coax)
following the guidelines in the Wire Use part of these
Instructions.
REV JAN 1983 3-7

Maintenance—TM S01
6. Wires or cables which may be at large potential
differences should be dressed or bundled so as to avoid
contact. Keep all interface wiring away from the TM 506
primary line wiring.
7. There is an empty cut-out which will mount the
standard IEC digital interface connector The connector is
not supplied with this option.
Wire Use.
1Hook up wire with square-pin receptacle on both
ends. These may be used tor low frequency or dc circuits
where impedance levels and crossstalk are not aproblem.
The wire is supplied in four lengths for connection
between compartments (adjacent or nonadjaceni) or
between acompartment and the rear panel For connec-
tion to the rear panel, cut to length then tin and solder the
end going to the rear panel
2Coaxial wire with square pin receptacles on both
ends. These are used for connections which require
shielding or which must maintain a50 0characteristic
impedance The outer conductor should be connected to
either chassis ground or circuit ground. Plug-in lines
which require coax leads usually have aspecified ground
pin assignment If necessary, establish auxiliary ground
connections at the appropriate wire ends The coaxial wire
IS supplied in four lengths for connection between com-
partments (adjacent or non-adjacent) or between acom-
partment and the rear panel. For connection to the rear
panel, cut to length then tin andsoldertheend going tothe
rear panel
Packaging Information
Alist of standard accessories (and part numbers) is
located mthe Replaceable Mechanical Parts list
If the Tektronix instrument is to be shipped to a
Tektronix Service Center for service or repair, attach alag
showing owner (with address) and the name of an
individual at your firm that can be contacted Include the
complete instrument serial number and adescription of
the service required
Save and re-use the package in which your Instrument
was shipped. If the original packaging is unfit for use or
not available, repackage the Instrument as follows:
Surround ihe instrument with polyethylene sheeting to
protect the finish of the instrument. Obtain acarton of
corrugated cardboard of the correct carton strength
and having inside dimensions of no less than 6inches
more than the instrument dimensions. Cushion the
instrument by tightly packing 3inches of dunnage or
urethane foam between carton and instrument on all
sides. Seat the carton with shipping tape or an in-
dustrial stapler
The carton test strength for this instrument Is 200
pounds per square inch.
INSTALLATION PROCEDURE
Due to regional variations in the power source line
voltage the TM SOI has selectable transformer primary
taps The taps are located on the interface board and are
implemented by using the appropriate selects block. See
Figs 3-3, 3-4, and 3-5.
Fig. 3-3. 220 VSelector block In service.
NOTE
On later serial numbers, the selector blocks are locat-
ed on the back side of the circuit board.
3-8 REV MAR 1962