Tektronix 1740A Series User manual

Service Manual
1740A Series, 1750A Series, & 1760 Series
Waveform/Vector Monitors
S/N B020000 and Above
070-8469-03
This document applies to firmware version 2.00
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 three (3) years 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.

1740A Series, 1750A Series, & 1760 Series Service Manual i
Table of Contents
General Safety Summary ix...................................
Service Safety Summary xi....................................
Preface xiii...................................................
Contacting Tektronix xiv.............................................
Specifications
Product Description 1--1..............................................
Input Format 1--13....................................................
Installation 2--1.....................................................
Standard Accessories 2--1.............................................
Mechanical Installation 2--2...........................................
Electrical Installation 2--8.............................................
Rear Panel Connectors 2--9............................................
Remote Connector 2--10...............................................
Remote Connector Converter 2--12.......................................
RS232 Connector 2--13................................................
Installing Software 2--14...............................................
Loading Software 2--16................................................
Calibrating New Features 2--20..........................................
Special Recovery for Power Loss During the Execution of UPGRADE 2--20.....
Operating Information
Getting Started 2--23..................................................
Operating Instructions 2--24............................................
General Menu Information 2--25.........................................
Functional Overview 2--27.............................................
Displaying a Signal 2--29...............................................
Theory of Operation
Block Diagram Description 3--1..................................
Block Diagram 1: Input and Waveform Monitor 3--1........................
Block Diagram 2: Vector -- SCH -- Component 3--3.........................
Block Diagram 3: Microprocessor and Line Rate Controller 3--5..............
Circuit Theory 3--7............................................
Diagrams <1> and <2> Channel A and Channel B Inputs 3--7...............
Diagram <3> Vertical Input 3--8........................................
Diagram <4> Vertical Output 3--10.......................................
Diagram <5> Horizontal 3--11..........................................
Diagram <6> Microprocessor 3--12......................................
Diagram <7> Dynamic Control 3--14.....................................
Diagram <8> Readout 3--15............................................
Diagram <9> DACS & Serial 3--16......................................
Diagram <10> Remote & 1760 Series / XROM Bus Connectors 3--16...........

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ii 1740A Series, 1750A Series, & 1760 Series Service Manual
Diagram <11> Z-Axis & Control 3--17....................................
Diagram <12> Front Panel 3--18.........................................
Diagram <13> DACs & Digital Control 3--18..............................
Diagram <14> Subcarrier Regenerator 3--19...............................
Diagram <15> Phase Shifter 3--21.......................................
Diagram <16> Demodulator 3--22.......................................
Diagram <17> Internal SCH 3--23.......................................
Diagram <18> Reference SCH 3--26.....................................
Diagram <19> Component Inputs, Transcoders, & RGB Outputs 3--28..........
Diagram <20> Component Control and Switching (1760 Series Only) 3--30......
Diagram <21> Low Voltage Power Supply 3--32............................
Diagram <22> High Volts Power Supply 3--35..............................
Performance Verification
Recommended Equipment List 4--1.....................................
Performance Check Procedure Short-Form Reference 4--6...................
Performance Check Procedure 4--19......................................
Adjustments
Required Equipment 5--1..............................................
Initial Setup 5--9....................................................
Functional Description of PC Display 5--10................................
Circuit Board Adjustment Locations 5--12.................................
Waveform Illustrations 5--15............................................
Maintenance
Preventing ESD 6--1.................................................
Preventive Maintenance 6--1...........................................
Performance Checks and Adjustments 6--2................................
Inspection and Cleaning 6--2...........................................
Replacing the Line Fuse 6--5...........................................
Troubleshooting 6--5.................................................
Corrective Maintenance 6--12....................................
Circuit Boards 6--12...................................................
Mechanical Disassembly/Assembly 6--13..................................
Removing the Bezel 6--13..........................................
Replacing the Graticule Light 6--14...................................
Removing the CRT 6--16...........................................
Removing the Rear Panel 6--19......................................
Removing the Front Panel and the Front Panel Circuit Board 6--21..........
Removing the Main Board 6--22.....................................
Removing the Power Supply Board 6--24..............................
Removing the Vector Board 6--25....................................
Removing the SCH Board
(1750A Series & 1760 Series Option SC only) 6--26..............
Removing the Component Board
(1760 Series only) 6--26.....................................
Repackaging 6--27....................................................

Table of Contents
1740A Series, 1750A Series, & 1760 Series Service Manual iii
Options and Accessories
Options 7--1........................................................
Standard Accessories 7--1.............................................
Optional Accessories 7--2.............................................
Replaceable Electrical Parts
Parts Ordering Information 8--1.........................................
Using the Replaceable Electrical Parts List 8--1............................
Diagrams/Circuit Board Illustrations
Replaceable Mechanical Parts
Parts Ordering Information 10--1.........................................
Using the Replaceable Mechanical Parts List 10--1..........................
Glossary
Index

Table of Contents
iv 1740A Series, 1750A Series, & 1760 Series Service Manual
List of Figures
Figure 2--1: Dimensions of the 1700F00 plain cabinet 2--2............
Figure 2--2: 1700F02 portable cabinet 2--3.........................
Figure 2--3: Rear view showing the securing screws 2--4.............
Figure 2--4: The WFM7F05 side-by-side rack adapter 2--5...........
Figure 2--5: A WFM7F05 with a blank front panel (1700F06) 2--5.....
Figure 2--6: WFM7F05 rack mount cabinet with a 1700F07 utility
drawer 2--6...............................................
Figure 2--7: Custom installation of an instrument 2--7...............
Figure 2--8: Rear panel connectors 2--9............................
Figure 2--9: Rear panel REMOTE connector. 2--10...................
Figure 2--10: Replacement adapter for 1740/1750 2--12...............
Figure 2--11: Rear panel RS232 connector 2--13.....................
Figure 2--12: Standard and alternate hookups for the 9-pin
connector 2--16.............................................
Figure 2--13: Standard and alternate hookups for 25-Pin PC
Connector 2--17.............................................
Figure 2--14: 1760 front panel 2--24................................
Figure 2--15: The CRT menu, with the bezel controls and buttons 2--25.
Figure 3--1: NTSC line count (U24) & color frame 1 SCH field pulse 3--26
Figure 3--2: PAL line count (U24) & color frame 1 SCH field pulse 3--27
Figure 3--3: Pinout of the CRT socket 3--35.........................
Figure 4--1: External Horizontal or RGB/YRGB Cable Adapter 4--4...
Figure 4--2: Remote Sync Cable Adapter 4--5......................
Figure 4--3: Audio and Timecode Cable Adapter 4--5................
Figure 4--4: Timing Cursor Check 4--16............................
Figure 4--5: Fast DC Restorer Response 4--24.......................
Figure 4--6: R--Y Display 4--27....................................
Figure 4--7: Audio Display 4--33..................................
Figure 4--8: Option Blanking Pulse 4--36...........................
Figure 4--9: Bowtie Common Mode Rejection Ratio 4--38.............
Figure 5--1: External horizontal/RGB and YRGB cable adapter 5--5...
Figure 5--2: Remote sync cable adapter 5--5........................
Figure 5--3: Audio and Timecode Cable Adapter 5--6................

Table of Contents
1740A Series, 1750A Series, & 1760 Series Service Manual v
Figure 5--4: RS232 cable standard and alternate connections for
9-pin PC connector 5--7.....................................
Figure 5--5: RS232 cable standard and alternate hookups for
25-pin PC connector 5--8....................................
Figure 5--6: Typical adjustment procedures PC screen display 5--10....
Figure 5--7: A1 Power Supply board 5--12..........................
Figure 5--8: A3 Main board 5--12..................................
Figure 5--9: A5 Vector board 5--13.................................
Figure 5--10: A6 SCH board 5--13.................................
Figure 5--11: A7 Component board 5--14...........................
Figure 5--12: Adjusting for thinnest luminance step 5--15.............
Figure 5--13: Matching flat and luminance filter responses 5--15.......
Figure 5--14: Adjusting the NTSC SCH on the oscilloscope 5--16.......
Figure 5--15: Matching the SCH dot flipping points 5--16.............
Figure 5--16: Adjusting the option blanking pulse 5--17...............
Figure 5--17: Adjusting for minimum Bowtie amplitude 5--17..........
Figure 5--18: Adjusting Diamond display phase 5--18.................
Figure 6--1: Instrument etched circuit board assemblies 6--12..........
Figure 6--2: Removing the CRT bezel 6--13.........................
Figure 6--3: Replacing graticule light bulbs 6--15....................
Figure 6--4: Removing the CRT 6--17..............................
Figure 6--5: Removing the rear panel and Input/BNC assembly 6--20...
Figure 6--6: Disassembling Input/BNC assembly A4/A4--A1 6--20.......
Figure 6--7: Removing the front--panel assembly 6--21................
Figure 6--8: Front Panel circuit board assembly 6--22.................
Figure 6--9: Screws holding the Main circuit board in place 6--23.......
Figure 6--10: Securing screws for the Power Supply circuit 6--24.......
Figure 6--11: Mounting hardware for the Vector and SCH circuit
boards 6--25................................................
Figure 6--12: Component circuit board mounting hardware 6--26......
Figure 6--13: Repackaging a 1740A, 1750A, or 1760 Series
instrument 6--27............................................
Figure 10--1: Exploded View 10--11.................................

Table of Contents
vi 1740A Series, 1750A Series, & 1760 Series Service Manual
List of Tables
Table 1--1: Waveform vertical deflection 1--3......................
Table 1--2: External reference 1--6..............................
Table 1--3: Waveform horizontal deflection 1--6...................
Table 1--4: Measurement cursors 1--7............................
Table 1--5: RGB/YRGB 1--7....................................
T a b l e 1 -- 6 : C a l i b r a t o r 1 -- 8.....................................
Table 1--7: Vector mode 1--8....................................
Table 1--8: Audio mode 1--9.....................................
Table 1--9: Time code 1--10......................................
Table 1--10: SCH Phase mode (1750 Series and
1760 Option SC Only) 1--10..................................
Table 1--11: Component vector mode (1760 Series Only) 1--12.........
Table 1--12: Lightning mode (1760 Series only) 1--12.................
Table 1--13: Bowtie mode (1760 Series only) 1--13...................
Table 1--14: Transcoded GBR outputs 1--13........................
Table 1--15: CRT display 1--14...................................
Table 1--16: Power source 1--14...................................
Table 1--17: Environmental characteristics 1--14....................
Table 1--18: Physical characteristics 1--15..........................
Table 1--19: Certifications and compliances 1--16....................
Table 2--1: Remote connector 2--11................................
Table 2--2: The available display modes 2--27.......................
Table 3--1: Transcoder signal mixing 3--28.........................
Table 3--2: Component display output switching 3--29...............
Table 4--1: Short-Form Performance Check 4--6....................
Table 4--2: Vector cursor readout values 4--17......................
Table 4--3: Audio and Timecode Values 4--32.......................
Table 6--1: External inspection check list 6--3......................
Table 6--2: Power supply fault symptoms 6--6......................
Table 6--3: Low volts supply voltages 6--6.........................
Table 6--4: Control Circuit Test Points 6--8........................
Table 6--5: Shut down logic levels 6--9............................