Tektronix WFM90D User manual

Service Manual
WFM90D and WFM91D
Handheld Waveform, Vector,
Picture, and Audio Monitor
071-1143-00
This document applies to firmware version 2.13
and above.
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.
www.tektronix.com

Copyright ©Tektronix, Inc. All rights reserved.
Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.
Tektronix, Inc., P.O. Box 500, Beaverton, OR 97077
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

WARRANTY
Tektronix warrants that the products that it manufactures and sells will be free from defects in materials and
workmanship for a period of one (1) year from the date of shipment. If a 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.
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, with
shipping charges prepaid. 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 integration increases the time
or difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX 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.

WFM90D and WFM91D Service Manual i
Table of Contents
General Safety Summary vii...................................
Service Safety Summary ix....................................
Preface xi...................................................
About This Manual xi...............................................
Related Manuals xi.................................................
Contacting Tektronix xii.............................................
Specifications
Specifications 1--1.............................................
Product Description 1--1..............................................
Characteristics Tables 1--2.............................................
Electrical Specifications 1--2...........................................
Physical Characteristics 1--7...........................................
Environmental Characteristics 1--8......................................
Certifications and Compliances 1--9.....................................
Operating Information
Installation 2--1...............................................
Mechanical Installation 2--1...........................................
Electrical Installation 2--4.............................................
Functional Overview 2--7.......................................
Keypad Controls 2--7.................................................
Side-Panel Connectors and Switches 2--10.................................
Onscreen Readouts 2--12...............................................
Using the Menus 2--15...........................................
Operating Menus 2--17................................................
Configuration Menu 2--21..............................................
Line Select Menu 2--26................................................
Theory of Operation
Theory of Operation 3--1.......................................
Input Board 3--1.....................................................
SDI Interface Board 3--1..............................................
Top Board 3-- 2......................................................
Bottom Board 3--2...................................................
Backlight Power Supply Board 3--2.....................................
LCD Display and Backlight 3--2........................................
Performance Verification
Performance Verification 4--1...................................
Summary Verification 4--2.............................................
Equipment Required 4--3..............................................
Performance Verification: Analog Section 4--5.....................

Table of Contents
ii WFM90D and WFM91D Service Manual
Sync Separation 4--5.................................................
Sweep Timing and Integral Linearity 4--6................................
Vertical Gain and Vertical Magnifier Registration 4--7.......................
Variable Gain Range and Vertical Position Range 4--7.......................
Overscan 4--8.......................................................
Input and DC Restorer Frequency Response 4--9...........................
Vector Phase Stability 4--11.............................................
Chrominance Bandwidth 4--12..........................................
Audio Gain and Frequency Response 4--13................................
Performance Verification: Digital Section 4--15......................
Check Sync Separation 4--15............................................
Check Frequency Response 4--16........................................
Check Frequency Response at X5 Gain 4--17...............................
Adjustment Procedures
Adjustments 5--1..............................................
Summary Adjustment 5--1.............................................
Equipment Required 5--2..............................................
Adjustment Procedures 5--3............................................
Adjustment Procedures: Analog Section 5--5.......................
Raster VCO 5--5.....................................................
Sweep Timing and Horizontal Mag Registration 5--5........................
Vertical Gain and X5 Gain Registration 5--7...............................
Frequency Response 5--7..............................................
Vector Quadrature Phase 5--9..........................................
VectorGainandX5GainPhase 5--9.....................................
Audio Gain 5--10.....................................................
Adjustment Procedures: Digital Section 5--11.......................
Vertical Gain 5--11....................................................
Frequency Response 5--12..............................................
VectorGainandX5GainPhase 5--12.....................................
Cable Margin 5--13...................................................
Maintenance
Maintenance 6--1..............................................
Cleaning 6--1.......................................................
After Repair Adjustments 6--2..........................................
Repackaging Instructions 6--2..........................................
Remove and Replace 6--3.......................................
Tools Required 6--3..................................................
Procedures 6--4......................................................
Troubleshooting Procedures 6--31.................................
Equipment Required 6--31..............................................
Battery-Fault Analysis 6--32............................................
Low-Voltage Power Supply 6--34........................................
Fault Symptom Table 6--35.............................................
Troubleshooting Flowcharts 6--36........................................
Connector Diagram 6--51..............................................

Table of Contents
WFM90D and WFM91D Service Manual iii
Options
Options 7--1..................................................
Options 7--1........................................................
Accessories 7--2.....................................................
Replaceable Mechanical Parts
Replaceable Parts List 8--1......................................
Parts Ordering Information 8--1.........................................
Using the Replaceable Parts List 8--2....................................
Diagrams
Diagrams 9--1.................................................

Table of Contents
iv WFM90D and WFM91D Service Manual
List of Figures
Figure 2--1: Installing the viewing hood 2--2.......................
Figure 2--2: Installing the desk stand 2--2..........................
Figure 2--3: Packing the Option 33 travel case 2--3..................
Figure 2--4: Removing the NiMH battery pack 2--5.................
Figure 2--5: Inside of the battery compartment, showing
polarity markings 2--6......................................
Figure 2--6: WFM90D keypad 2--8...............................
Figure 2--7: WFM90D and WFM91D side panels 2--11...............
Figure 2--8: Onscreen readout messages 2--12.......................
Figure 2--9: Waveform and Vector menus 2--15......................
Figure 2--10: Audio, Picture, and Waveform-in-Picture menus 2--16....
Figure 2--11: Line Select menu 2--16...............................
Figure 2--12: Configuration menu 2--22............................
Figure 3--1: Simplified block diagram 3--3.........................
Figure 4--1: --3 dB marks on the vector graticule 4--12................
Figure 5--1: NTSC graticule showing the vector gain adjustment 5--10..
Figure 6--1: Removing the top cover 6--5..........................
Figure 6--2: Installing the LCD display cable 6--7...................
Figure 6--3: Installing the LCD display 6--9........................
Figure 6--4: Installing the keypad 6--12............................
Figure 6--5: Installing the Top board shield 6--13....................
Figure 6--6: Installing the Bottom board 6--15.......................
Figure 6--7: Installing the SDI Interface board 6--16..................
Figure 6--8: Installing the battery cover 6--19.......................
Figure 6--9: Removal and replacement of the turnlock stud 6--20.......
Figure 6--10: Removing the NiMH battery pack 6--22................
Figure 6--11: Installed polarity of alkaline batteries 6--23..............
Figure 6--12: Battery contact installation alignment 6--25.............
Figure 6--13: Battery power-wire and turnlock stud receptacle
installation 6--26............................................
Figure 6--14: Battery orientation marker position 6--28...............
Figure 6--15: Installing the EMI suppressor 6--29....................

Table of Contents
WFM90D and WFM91D Service Manual v
Figure 6--16: Testing the battery charging circuit 6--32................
Figure 6--17: Flowchart for no display 6--37........................
Figure 6--18: Flowchart for distorted waveform display 6--38..........
Figure 6--19: Flowchart for no vector display 6--39...................
Figure 6--20: Flowchart for problems processing serial digital
input signals 6--40...........................................
Figure 6--21: Flowchart for bad audio display 6--41..................
Figure 6--22: Flowchart for no picture display 6--42..................
Figure 6--23: Flowchart for bad graticules and menus 6--43...........
Figure 6--24: Flowchart for all white display 6--44...................
Figure 6--25: Flowchart for untriggered waveform display 6--45........
Figure 6--26: Flowchart for unlocked vector display 6--46.............
Figure 6--27: Flowchart for vector display jitter 6--47.................
Figure 6--28: Flowchart for distorted vectors 6--47...................
Figure 6--29: Flowchart for problems with the instrument
controls 6--48...............................................
Figure 6--30: Flowchart for bad menus in the picture display 6--49.....
Figure 6--31: Flowchart for dim or blotchy display 6--50..............
Figure 6--32: Flowchart for bad displays except Picture mode 6--50.....
Figure 6--33: Circuit board connector and pin locations 6--51..........
Figure 8--1: Exploded view 8--4..................................
Figure 9--1: Interconnect diagram 9--1............................

Table of Contents
vi WFM90D and WFM91D Service Manual
List of Tables
Table 1--1: Vertical deflection system 1--2.........................
Table 1--2: DC restoration 1--4...................................
Table 1--3: Audio mode 1--5.....................................
Table 1--4: Horizontal deflection system 1--5......................
Table 1--5: Vector mode 1--6....................................
Table 1--6: Synchronization 1--7.................................
Table 1--7: Power source 1--7...................................
Table 1--8: Physical characteristics 1--7..........................
Table 1--9: Environmental characteristics 1--8.....................
Table 1--10: Certifications and Compliances 1--9...................
Table 2--1: Video readout messages 2--13...........................
Table 2--2: Waveform menu choices, analog and digital 2--18..........
Table 2--3: Vector menu choices, analog and digital 2--18.............
Table 2--4: Audio menu choices 2--19..............................
Table 2--5: Picture menu choices, analog and digital 2--19............
Table 2--6: WIP menu choices, analog and digital 2--20...............
Table 2--7: Configure menu choices 2--23..........................
Table 2--8: Default instrument settings 2--25........................
Table 2--9: Line Select menu choices 2--26..........................
Table 4--1: Summary verification procedure 4--2...................
Table 4--2: Equipment required for performance verification 4--3.....
Table 5--1: Summary adjustment 5--1............................
Table 5--2: Equipment required for adjustments 5--2...............
Table 6--1: Tools required for module removal 6--3.................
Table 6--2: Remove and replace procedure list 6--4.................
Table 6--3: Equipment required for troubleshooting 6--31............
Table 6--4: Low-voltage power supplies 6--34.......................
Table 6--5: Fault symptom table 6--35.............................
Table 7--1: Options 7--1........................................
Table 7--2: Standard accessories 7--2.............................
Table 7--3: Optional accessories 7--2..............................

WFM90D and WFM91D Service Manual vii
General Safety Summary
Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it. To avoid potential hazards, use this
product only as specified.
Only qualified personnel should perform service procedures.
Use Proper Power Cord. Use only the power cord specified for this product and
certified for the country of use.
Connect and Disconnect Properly. Do not connect or disconnect probes or test leads
while they are connected to a voltage source.
Observe All Terminal Ratings. 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.
Replace Batteries Properly. Replace batteries only with the proper type and rating
specified.
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.
Use Proper Fuse. Use only the fuse type and rating specified for this product.
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.
Keep Product Surfaces Clean and Dry.
ToAvoidFireor
Personal Injury

General Safety Summary
viii WFM90D and WFM91D Service Manual
Safety Terms and Symbols
Terms in This Manual. These terms may appear in this manual:
WARNING. Warning statements identify conditions or practices that could result
in injury or loss of life.
CAUTION. Caution statements identify conditions or practices that could result in
damage to this product or other property.
Terms on the Product. These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you read the
marking.
WARNING indicates an injury hazard not immediately accessible as you read the
marking.
CAUTION indicates a hazard to property including the product.
Symbols on the Product. These symbols may appear on the product:
CAUTION
Refer to Manual
Double
Insulated
This product contains a Nickel battery, which must be recycled or disposed of
properly. For the location of a local battery recycler in the U.S. or Canada, please
contact:
RBRC (800) BATTERY
Rechargeable Battery Recycling Corp. [phone]
P.O. Box 141870
www.rbrc.com
Gainesville, Florida 32614
Battery Recycling

WFM90D and WFM91D Service Manual ix
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.

Service Safety Summary
xWFM90D and WFM91D Service Manual

WFM90D and WFM91D Service Manual xi
Preface
This manual provides instructions for servicing the WFM90D and WFM91D
Handheld Waveform, Vector, Picture, and Audio Monitors. This manual
describes features and specifications that are common to all generator modules.
These include system configuration and the common control interface.
About This Manual
This manual is composed of the following sections:
HSpecifications lists the electrical and environmental specifications and
provides a general product description.
HOperating Information describes installation and front panel operation of the
instrument.
HTheory of Operation contains a module-level description based on block
diagrams of the instrument circuitry.
HPerformance Verification provides procedures for verifying instrument
performance.
HAdjustment Procedures provides procedures for adjusting the instrument to
meet performance levels listed in Specifications.
HMaintenance contains instructions for cleaning the instrument, procedures
for removal and replacement of instrument modules, and troubleshooting
procedures.
HOptions lists all of the options that you might find on your instrument.
HReplaceable Mechanical Parts lists the part numbers of the replaceable
electrical and mechanical parts and assemblies.
HDiagrams contains the instrument interconnect diagram.
Related Manuals
The WFM90D & WFM91D Handheld Waveform, Vector, Picture, & Audio
Monitor User Manual (Tektronix part number 071-1142-XX) describes in detail
how to operate the instrument.

Preface
xii WFM90D and WFM91D Service Manual
Contacting Tektronix
Phone [phone]*
Address Tektronix, Inc.
Department or name (if known)
14200 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA
Web site www.tektronix.com
Sales support 1-800-833-9200, select option 1*
Service support 1-800-833-9200, select option 2*
Technical support Email: [e-mail]
1-800-833-9200, select option 3*
6:00 a.m. -- 5:00 p.m. Pacific time
*This phone number is toll free in North America. After office hours, please leave a
voice mail message.
Outside North America, contact a Tektronix sales office or distributor; see the
Tektronix web site for a list of offices.

Specifications

WFM90D and WFM91D Service Manual 1-1
Specifications
This section includes the following information:
HProduct description
HSpecifications tables
Product Description
The handheld, self-contained, Tektronix WFM90D and WFM91D television
waveform monitors can monitor analog and digital signals. The monitors provide
composite and component waveform displays as well as vector and picture
displays.
These monitors can be used in the traditional in-house applications of television
production, post-production, and signal transmission. In addition, their portabili-
ty allows them to be used in non-traditional applications such as field production
and system maintenance.
HAccepts NTSC/PAL composite video or 525/625 Component 270 Mbit serial
digital video signals
HAutomatic detection of analog or serial digital signals
HBuilt-in color display (TFT LCD)
HViewing angle control
HElectronic graticules
HBattery or AC adapter powered
HMenu-assisted monitoring operation
HAudio signal input/output
HWaveform, Vector, Picture, Audio, and Waveform-in-Picture display modes
HLine select lets you view any single line of video
HSelectable time out for backlight or instrument power
HSignal level alarm mode for waveform and audio displays
HPreset menu to store/recall front panel and menu setups
HInstrument adjustments from front panel (see service manual)
Key Features

Specifications
1-2 WFM90D and WFM91D Service Manual
Characteristics Tables
The tables use the following abbreviations:
Performance Requirement (Req). All performance requirements in the specifica-
tion tables are identified with Req, and can be assured by completing the
Performance Check Procedure located in the service manual. Allow a warm-up
time of 20 minutes.
Performance requirements in the electrical specifications are valid over an
ambient temperature range of +20°Cto+30°C. The Performance Requirement
tolerances listed in the Electrical Specification are doubled over the temperature
range of 0°Cto+40° C, unless otherwise specified. Test equipment used to
verify Performance Requirements must be calibrated and working within the
limits specified in the service manual Equipment Required List.
Reference Information.Information that amplifies a performance requirement or
is of special importance is indicated by REF. There is no need to check these
items to a specific tolerance.
Electrical Specifications
Table 1- 1: Vertical deflection system
Category Description
Frequency Response
Analog Input REF: Specifications apply for full screen height video input signal, with VARIABLE GAIN off.
REQ: Flat Filter 1 V Full Scale:
50 kHz to 6 MHz within 2% of response at 50 kHz.
REQ: Flat Filter X5 Gain:
50 kHz to 6 MHz within 5% of response at 50 kHz.
REF: Low Pass Filter:
≥40 dB attenuation at 3.58 MHz NTSC, 4.43 MHz PAL.
REF: Response at 15 kHz does not vary between FLAT and LUM (low pass) filters by more than 1%.
Digital Input REF: Specifications apply for full screen height video input signal, with VARIABLE GAIN off.
REQ: Flat Filter 1 V Full Scale:
50 kHz to 4.5 MHz ±4%.
REQ: Flat Filter X5 Gain:
50 kHz to 4.5 MHz ±5%.
REF: Low Pass Filter:
≥40 dB attenuation at 3.58 MHz NTSC, 4.43 MHz PAL.
REF: Response at 15 kHz does not vary between FLAT and LUM (low pass) filters by more than 1%.