Tektronix VM101, VM100 Service Manual

Service Manual

VM100 & VM101 Video Measurment Set

070-9288-02

This document supports firmware version 1.64 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.

that in all previously published material. Specifications and price change privileges reserved. Printed in the U.S.A. T ektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070–1000 TEKTRONIX and TEK are registered trademarks of T ektronix, Inc.

WARRANTY

T ektronix 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, T ektronix, 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 T ektronix, with shipping charges prepaid. T ektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the T ektronix 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. T ektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting from attempts by personnel other than T ektronix 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-T ektronix 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 REP AIR 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.

Service Assurance

If you have not already purchased Service Assurance for this product, you may do so at any time during the product’s warranty period. Service Assurance provides Repair Protection and Calibration Services to meet your needs.

Repair Protection extends priority repair services beyond the product’s warranty period; you may purchase up to three years of Repair Protection.

Calibration Services provide annual calibration of your product, standards compliance and required audit documentation, recall assurance, and reminder notification of scheduled calibration. Coverage begins upon registration; you may purchase up to five years of Calibration Services.

Service Assurance Advantages

H Priced well below the cost of a single repair or calibration H Avoid delays for service by eliminating the need for separate purchase authorizations from your company H Eliminates unexpected service expenses

For Information and Ordering

For more information or to order Service Assurance, contact your T ektronix representative and provide the information below . Service Assurance may not be available in locations outside the United States of America.

Name VISA or Master Card number and expiration Company date or purchase order number Address Repair Protection (1,2, or 3 years) City , State, Postal code Calibration Services (1,2,3,4, or 5 years) Country Instrument model and serial number Phone Instrument purchase date

Specifications

Operating Information

General Safety Summary vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Service Safety Summary ix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Preface xi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Related Manuals xi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Service Manual Conventions xi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Contacting T ektronix xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Product Description 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Specification T ables 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

T erms Used in Specifications 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Performance Conditions 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electrical Specifications 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Environmental Characteristics 1–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Safety Standards and Certification 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Physical Characteristics 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Remote Control Port 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Theory of Operation

Installation 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power Source Requirements 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating Information 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Front Panel Buttons and LCD Display 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Menus 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rear Panel Connectors 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power On Procedure 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Configuration 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Logic Conventions 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Block Level Description 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DC Restore 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sync Stripper 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gain, DC Offset, and Filtering 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Phase Lock Loop 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Analog-to-Digital Converter 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Digital Signal Processor 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Acquisition Control 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Host Processor and Memory 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Remote Interface (RS232) 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Front Panel 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

LCD Display 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power Supply 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Detailed Circuit Description 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VM100 & VM101 Service Manual

Table of Contents

Performance Verification

General Information 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Prerequisites 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Equipment Requirements 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

T est Record 4–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Performance Verification Procedure 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DC Restore 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sync Stripper 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gain, DC Offset, and Filtering 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Phase Lock Loop 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A/D Converter 3–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Digital Signal Processor (DSP) 3–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Acquisition Control 3–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Host Processor and Memory 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Remote Interface (RS232) 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Front Panel 3–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

LCD Display 3–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power Supply 3–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Purpose 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

T est Interval 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Initial Setup 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Configure the Video Measurement Set 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Signal Identification T est 4–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Differential Phase Test 4–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Differential Gain Test 4–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sync Amplitude T est 4–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Burst Amplitude T est 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bar Amplitude T est 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2T K-factor Test 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chrominance-to-Luminance Delay T est 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chrominance-to-Luminance Gain T est 4–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Luminance Nonlinearity T est 4–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Group Delay T est 4–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Frequency Response T est 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Adjustment Procedures

General Information 5–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Purpose 5–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Adjustment Interval 5–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Requirements 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Personnel 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Warmup Period 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Access 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Required T est Equipment 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Adjustment Procedure 5–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Interrupting the Adjustments 5–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Performing the Adjustments 5–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VM100 & VM101 Service Manual

Maintenance

Table of Contents

Preventing ESD 6–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Battery Disposal 6–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Inspection and Cleaning 6–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General Care 6–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Inspection and Cleaning Procedures 6–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal and Replacement Procedures 6–7. . . . . . . . . . . . . . . . . . . . . . . . .

Preparation 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Summary of Procedures 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

T ools Required 6–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

T op Cover 6–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Front Panel 6–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Main Board 6–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power Supply 6–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

LCD Board 6–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lithium Battery 6–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting 6–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Equipment Required 6–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

T esting the Lithium Battery 6–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power Supply Limits 6–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting the main board (A2) 6–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Examples of Analog Signal Measurements 6–21. . . . . . . . . . . . . . . . . . . . . . . . .

Phase Lock and DSP Diagnostic LEDs and Key Signals 6–25. . . . . . . . . . . . . . .

ACQ:SHOW Command 6–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting the VM140 or VM141 System 6–30. . . . . . . . . . . . . . . . . . . . .

Repackaging Instructions 6–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Packaging 6–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage 6–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Options

Standard Accessories 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Optional Accessories 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Options 7–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Replaceable Electrical Parts

Parts Ordering Information 8–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Using the Replaceable Electrical Parts List 8–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Diagrams

Symbols 9–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Component Values 9–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Graphic Items and Special Symbols Used in This Manual 9–2. . . . . . . . . . . . . . . . .

Component Locator Diagrams 9–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Replaceable Mechanical Parts

Parts Ordering Information 10–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Using the Replaceable Mechanical Parts List 10–1. . . . . . . . . . . . . . . . . . . . . . . . . . .

VM100 & VM101 Service Manual

iii

Table of Contents

List of Figures

Figure 2–1: Front panel 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–2: LCD display characteristics 2–3. . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–3: The Meas, Mem, and Print menus 2–4. . . . . . . . . . . . . . . . . .

Figure 2–4: The CONFIG menu 2–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–5: Rear panel connectors 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 3–1: Simplified view of Gain, DC Offset, and Filtering block 3–5

Figure 3–2: Acquisition and DSP system 3–8. . . . . . . . . . . . . . . . . . . . . . .

Figure 3–3: Host processor and memory system 3–10. . . . . . . . . . . . . . . . .

Figure 4–1: Initial setup for the PV procedure 4–4. . . . . . . . . . . . . . . . . . .

Figure 5–1: Equipment setup for the adjustment procedure 5–4. . . . . . .

Figure 6–1: Top cover replacement 6–8. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 6–2: Front panel assembly replacement 6–9. . . . . . . . . . . . . . . . . .

Figure 6–3: Front panel board replacement 6–10. . . . . . . . . . . . . . . . . . . . .

Figure 6–4: Main board removal 6–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 6–5: Front panel assembly removal 6–12. . . . . . . . . . . . . . . . . . . . . .

Figure 6–6: Power supply board replacement 6–13. . . . . . . . . . . . . . . . . . .

Figure 6–7: LCD board replacement 6–15. . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 6–8: Lithium battery replacement 6–16. . . . . . . . . . . . . . . . . . . . . . .

Figure 6–9: Power supply test points and limits 6–19. . . . . . . . . . . . . . . . . .

Figure 6–10: Location of diagnostic LEDs 6–21. . . . . . . . . . . . . . . . . . . . . .

Figure 6–11: Setup for measuring analog signals 6–22. . . . . . . . . . . . . . . . .

Figure 6–12: Waveform at A2TP9 6–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 6–13: Waveform at A2TP10 6–23. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 6–14: VIDEO waveform at A2TP31 6–24. . . . . . . . . . . . . . . . . . . . .

Figure 6–15: COMP_SYNC waveform at A2TP15 6–24. . . . . . . . . . . . . . .

Figure 6–16: FIELD waveform at A2TP16 6–25. . . . . . . . . . . . . . . . . . . . . .

Figure 6–17: 8FSC_IN waveform at A2U116 pin 7 6–26. . . . . . . . . . . . . . .

Figure 6–18: HPULSE waveform at A2TP18 6–27. . . . . . . . . . . . . . . . . . . .

Figure 6–19: DSP_RCK waveform at A2U48 pin 1 6–27. . . . . . . . . . . . . . .

Figure 6–20: Example of the ACQ:SHOW command PC display 6–28. .

Figure 6–21: Setup for using the ACQ:SHOW command 6–29. . . . . . . . .

Figure 9–1: Interconnect diagram 9–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VM100 & VM101 Service Manual

Table of Contents

Figure 9–2: Block diagram 9–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 9–3: A2 Main board view A (671-3250-00/01/02/03) 9–5. . . . . . . .

Figure 9–4: A2 Main board view B (671-3250-00/01/02/03) 9–6. . . . . . . .

Figure 9–5: A2 Main board view C (671-3250-00/01/02/03) 9–7. . . . . . . .

Figure 9–6: A2 Main board component locator

(671-3250-00/01/02/03) 9–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 9–7: A2 Main board view A (671-3751-00) 9–9. . . . . . . . . . . . . . . .

Figure 9–8: A2 Main board view B (671-3751-00) 9–10. . . . . . . . . . . . . . . .

Figure 9–9: A2 Main board section C (671-3751-00) 9–11. . . . . . . . . . . . . .

Figure 9–10: A2 Main board component locator (671-3751-00) 9–12. . . . .

Figure 9–11: A1 Front Panel board 9–26. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 10–1: Exploded view 10–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VM100 & VM101 Service Manual

Table of Contents

List of Tables

Table 1–1: Input signal requirements–VIDEO INPUT 1–3. . . . . . . . . . .

Table 1–2: Input signal requirements–EXT REF 1–3. . . . . . . . . . . . . . . .

Table 1–3: Measurement accuracy 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 1–4: Output 1–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 1–5: AC power source 1–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 1–6: Environmental characteristics 1–5. . . . . . . . . . . . . . . . . . . . . .

Table 1–7: Certifications and compliances 1–6. . . . . . . . . . . . . . . . . . . . . .

Table 1–8: Physical characteristics 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 1–9: Remote control port 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 2–1: Configuration parameters 2–7. . . . . . . . . . . . . . . . . . . . . . . . .

Table 2–2: Print parameters 2–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 2–3: Computer interface parameters 2–13. . . . . . . . . . . . . . . . . . . . .

Table 2–4: Date parameters 2–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 2–5: Time parameters 2–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 3–1: Power-on diagnostics 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 4–1: Test Equipment 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 5–1: Adjustments after repair 5–1. . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 5–2: Required test equipment 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 5–3: Adjustment steps 5–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 6–1: Relative susceptibility to static discharge damage 6–2. . . . . .

Table 6–2: External inspection check list 6–4. . . . . . . . . . . . . . . . . . . . . . .

Table 6–3: Internal inspection check list 6–4. . . . . . . . . . . . . . . . . . . . . . .

Table 6–4: Tools required for module replacement 6–8. . . . . . . . . . . . . . .

Table 6–5: Power-on diagnostics 6–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 6–6: Control mode communications parameters 6–31. . . . . . . . . . .

Table 7–1: Power cord identification 7–2. . . . . . . . . . . . . . . . . . . . . . . . . .

VM100 & VM101 Service Manual

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.

If this equipment is used in any manner not specified, including failure to follow any rating or direction for use, the protection provided by the equipment may be impaired.

Injury Precautions

Product Damage

Precautions

Use Proper Power Cord. To avoid fire hazard, use only the power cord specified

for this product. Avoid Overvoltage. To avoid electric shock or fire hazard, do not apply potential

to any terminal, including the common terminal, that varies from ground by more than the maximum rating for that terminal.

Ground the Product

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.

Do Not Operate Without Covers. To avoid electric shock or fire hazard, do not operate this product with covers or panels removed.

Use Proper Fuse. To avoid fire hazard, use only the fuse type and rating specified for this product.

Do Not Operate in Wet/Damp Conditions. To avoid electric shock, do not operate this product in wet or damp conditions.

Do Not Operate in an Explosive Atmosphere. To avoid injury or fire hazard, do not operate this product in an explosive atmosphere.

Use Proper Power Source. Do not operate this product from a power source that applies more than the voltage specified.

. This product is grounded through the grounding conductor

Provide Proper Ventilation. To prevent product overheating, provide proper

ventilation. Do Not Operate With Suspected Failures. If you suspect there is damage to this

product, have it inspected by qualified service personnel.

Symbols and Terms

VM100 & VM101 Service Manual

T erms in this Manual. These terms may appear in this manual:

vii

General Safety Summary

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.

T erms 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. The following symbols may appear on the product:

Certifications and

Compliances

DANGER

High Voltage

Protective Ground

(Earth) T erminal

ATTENTION

Refer to Manual

Double

Insulated

Refer to the specifications section for a listing of certifications and compliances that apply to this product.

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VM100 & VM101 Service Manual

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.

Disconnect Power. To avoid electric shock, disconnect the main power by means of the power cord or, if provided, the power switch.

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.

VM100 & VM101 Service Manual

Service Safety Summary

VM100 & VM101 Service Manual

Preface

Use this manual to service the video measurement set to the module or component level. Contact your local Tektronix service center or sales engineer for more information on repair and adjustment services.

Related Manuals

The VM100 & VM101 Video Measurement Sets User Manual (Tektronix part number 070-9522-XX) describes how to use the video measurement set.

Service Manual Conventions

In this manual, the term “module” refers to any field-replaceable component, assembly, or part of the video measurement set.

Strategy for Servicing

To prevent personal injury or instrument damage:

H This product should be serviced only by a qualified service person H Read the General and Service Safety Summaries at the front of this manual,

as well as Operating Information beginning on page 2–1 H Follow all warnings, cautions, and notes in this manual

Adjustment Interval

Generally, you should perform the Adjustment Procedures once a year. In addition, perform the procedures after module replacement.

Tektronix Service Offerings

Tektronix provides service to cover repair under warranty as well as other services that may provide a cost-effective answer to your service needs.

Whether providing warranty repair service or any of the other services listed below, Tektronix service technicians are well equipped to service the video measurement set. Tektronix technicians train on Tektronix products and have access to the latest information on product improvements and new options.

VM100 & VM101 Service Manual

Preface

Warranty Repair Service

At-Depot Repair or

Calibration Service

Module Exchange

Contacting Tektronix

Tektronix warrants this product for one year from date of purchase. The warranty appears behind the title page in this manual. Tektronix technicians provide warranty service at most Tektronix service locations worldwide. The Tektronix product catalog lists all service locations worldwide.

The following services can be purchased to meet to your repair/calibration needs.

H A single repair and/or adjustment H Calibrations using equipment and procedures that meet the traceability

standards specific to the local area

H Annual maintenance agreements that provide for either calibration and

repair, or calibration only.

Reduce down time for repair by exchanging modules for remanufactured ones. Tektronix ships an updated and tested exchange module from the Beaverton, Oregon service center, typically within 24 hours. Each module comes with a 90-day service warranty.

Product Support

Service Support

For other information

To write us Tektronix, Inc.

For application-oriented questions about a Tektronix measurement product, call toll free in North America: 1-800-TEK-WIDE (1-800-835-9433 ext. 2400) 6:00 a.m. – 5:00 p.m. Pacific time

Or contact us by e-mail: tm_app_supp@tek.com

For product support outside of North America, contact your local Tektronix distributor or sales office.

Contact your local Tektronix distributor or sales office. Or visit our web site for a listing of worldwide service locations.

http://www.tek.com In North America:

1-800-TEK-WIDE (1-800-835-9433) An operator will direct your call.

P.O. Box 1000 Wilsonville, OR 97070-1000

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VM100 & VM101 Service Manual

Specifications

Product Description

This chapter provides a complete description of the specifications. Product Description is a general description of the instrument. The Specification Tables,

which begin on page 1–2, contain the complete specifications.

The Tektronix VM100 and VM101 Video Measurement Sets are automatic video measurement instruments. The VM100 measures NTSC signals and the VM101 measures PAL signals.

The video measurement sets use existing or inserted test signals and take measurements consistent with regulatory specifications.

The video measurement sets display measurement results on a LCD screen. You can also display measurement results on a serial printer or remote PC using the RS-232 port. The video measurement sets perform the following measurements (on-screen labels are shown in parentheses):

Differential Phase (DIFF PHASE)

Differential Gain (DIFF GAIN)

Chrominance-to-Luminance Delay (YC DELAY)

Chrominance-to-Luminance Gain (YC GAIN)

Signal-to-Noise Ratio (SNR WGT/FLAT)

Frequency Response (FREQ FCC or AVG)

Frequency Response Detail (FREQ FLAG, FREQ #1 through FREQ #6) or

(FRQmax and FRQmin)

Group Delay (GRPDLYmax and GRPDLYmin)

Sync Amplitude (SYNC AMPL)

Burst Amplitude (BURST AMPL)

Bar Amplitude (BAR AMPL)

2T K-Factor (2T K-FACTOR)

Luminance Nonlinearity (LUM NON-LIN)

Hum (HUM P-P, 50/60 Hz, and 100/120 Hz)

VM100 & VM101 Service Manual

1–1

Specifications

Specification Tables

This section provides a complete description of the video measurement set specifications. Refer to the Performance Conditions for a description of the required temperature range and other pertinent operating conditions.

Terms Used in Specifications

Performance Conditions

Characteristic. A characteristic refers to a property of the product. Performance Requirement [REQ]. Performance Requirements define

characteristics that are essential to the intended application of the product, usually in limit form.

Reference Information [RI]. Reference Information explains the performance requirements or stipulates conditions under which the performance requirements are effective. Reference information is not considered to be a statement of guaranteed performance.

Specification. A specification is a document or a section of a document that lists and describes characteristics and performance requirements of a product.

Typical. Typical refers to instrument performance that can be expected but is not guaranteed.

The performance requirements listed in the Electrical Specifications apply over an ambient temperature range of 0° C to +50° C. The rated accuracies are valid over the entire 0° C to 50° C range and become “typical” for temperatures from –10° C to 0° C. Test equipment used to verify performance requirements must be calibrated and working within the specified limits.

All specifications (with the exception of Signal-to-Noise Ratio Measurement Accuracy) apply for Signal-To-Noise Ratio ≥ 52 dB (weighted). Averaging (AVG) is enabled for all specifications.

1–2

VM100 & VM101 Service Manual

Electrical Specifications

T able 1–1: Input signal requirements–VIDEO INPUT

Category Description

Maximum Operating Voltage REQ: –1.8 V to +2.2 V Absolute Maximum Input Voltage REQ: –8.5 V to +8.5 V Minimum Operating Voltage REQ: 1 Vp-p video signal

RI: Typically operates with a 1 Vp-p input, +1 dB or –6 dB

DC Input Impedance REQ: ≥20 KW

RI: DC coupling

Return Loss REQ: >40 dB to 6 MHz

RI: DC coupling

Specifications

T able 1–2: Input signal requirements–EXT REF

Category Description

Absolute Maximum Input Voltage REQ: –8.5 V to +8.5 V Minimum Operating Voltage REQ: 1 Vp-p video signal

RI: Typically operates with a 1 Vp-p input, +1 dB or –6 dB DC Input Impedance REQ: ≥20 KW Return Loss REQ: >40 dB to 6 MHz Video INPUT / EXT REF

Loop-through Isolation RI: >70 dB (typical) Crosstalk REQ: >70 dB to 6 MHz

T able 1–3: Measurement accuracy

Environmental Characteristics

T able 1–6: Environmental characteristics

Safety Standards and Certification

T able 1–7: Certifications and compliances

Category Description

Altitude (Maximum Operating)

See page 1–5 for additional information C

US Nationally Recognized Testing Laboratory Listing

Canadian Certification

European Union Compliance Low Voltage Directive 73/23/EEC, Amended by 93/68/EEC Additional

Compliance

EC Declaration of Conformity

Operating: to 6,500 f (2000 m)

ANSI/ISA S82

Safety Standard for Electrical and Electronic Test, Measuring, Controlling, and Related Equipment

CAN/CSA C22.2 No.1010.1

Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use

UL31 11-1

Standard for Electrical Measuring and Test Equipment

IEC 1010-1

Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use

Meets intent of Directive 89/336/EEC for Electromagnetic Compatibility and Low Voltage Directive 73/23/ECC for Product Safety. Compliance was demonstrated to the following specifications as listed in the Official Journal of the European Communities:

EMC Directive 89/336/EEC: EN 50081-1 Emissions:

EN 55022 Class B Radiated and Conducted

Emissions

EN 50082-1 Immunity:

IEC 801-2 Electrostatic Discharge Immunity IEC 801-3 RF Electromagnetic Field Immunity IEC 801-4 Electrical Fast T ransient/Burst

Immunity

Low Voltage Directive 73/23/EEC: EN 61010-1 Safety requirements for electrical

equipment for measurement, control, and laboratory use

Using high quality shielded cables.

Equipment Type Test and Measuring FCC Compliance Emissions comply with FCC Code of Federal Regulations 47, Part 15, Subpart B,

Class A Limits

1–6

VM100 & VM101 Service Manual

T able 1–7: Certifications and compliances (cont.)

erial Port

Category Description

Overvoltage Category Overvoltage Category II (as defined in IEC 1010-1, Annex J) Pollution Degree Pollution Degree 2 (as defined in IEC 1010-1); rated for indoor use only Safety Class Class I (as defined in IEC 1010-1, Annex H) T emperature (Operating) +5° C to +50° C (+41° F to 122° F)

Physical Characteristics

T able 1–8: Physical characteristics

Category Description

Dimensions Height: 1.71 in (4.34 cm) Nominal

Width: 8.1 in (20.6 cm) Nominal

Depth: 17.2 in (43.7 cm) Nominal Stand-Alone Instrument Weight 4.00 lbs (1.81 kg) Nominal Packaged Weight (for domestic shipment) 7.12 lbs (3.23 kg) Nominal

Specifications

Remote Control Port

T able 1–9: Remote control port

Category Description

RS232 S

12345

6789

Connector: Nine-pin DCE female

Baud Rate: 1200, 2400, 9600, or 19.2K

Pin Signal Name RS232-C Name

Not Used TX (Transmit Data; Output) RX (Receive Data; Input) Not Used GND (Signal Ground) Not Used RTS (Request to Send; Output) CTS (Clear to Send; Input) Not Used

BA BB

AB CA

VM100 & VM101 Service Manual

1–7

Specifications

1–8

VM100 & VM101 Service Manual

Operating Information

This section describes how to operate the video measurement set. The operating information is limited to the functions required to perform the procedures found in this manual. More detailed operating instructions can be found in the VM100 & VM101 Video Measurement Sets User Manual (Tektronix part number 070-9522-XX).

The Operating Information is divided into the following sections: H Installation describes the power source requirements and explains where to

find a list of the power cord options

H Operating Information on page 2–1 describes the front panel buttons and

LCD display, the menus, the rear panel connectors, the power on procedure, and configuration instructions

Installation

Power Source Requirements

Operating Information

The video measurement set operates over the range of 90 V either 50 Hz or 60 Hz. The power source should never apply more than 250 V between the supply conductors or between either supply conductor and ground.

WARNING. To avoid personal injury due to electrical shock, never operate the video measurement set without the protective ground connection by way of the grounding conductor in the power cord.

This section provides the information you will need to operate the video measurement set when performing the procedures in this manual. It contains the following information:

H Descriptions of the front panel buttons and the LCD display H Descriptions of the menus H Descriptions of the rear panel connectors H Power on procedure

to 250 V

rms

H Configuration instructions for each operating mode

VM100 & VM101 Service Manual

2–1

Operating Information

Front Panel Buttons and

LCD Display

The front panel contains twelve buttons and an LCD display as shown in Figure 2–1. There are seven function buttons, four arrow buttons, and the enter button. A green LED indicator, located at the center of each function button, lights to show when the associated function is turned on. The arrow buttons are designated by directional arrows. A carriage return symbol (↵) identifies the enter button.

1 2 4

9 8 7 6

Figure 2–1: Front panel

Five of the function buttons (MEAS, SIG ID, MEM, PRINT, and CONFIG) are exclusive to each other. This means that only one of the functions can be active at a time. When you press another of these buttons, the previous function automatically turns off.

The following descriptions refer to Figure 2–1.

MEAS. Press the measure button to display the results of measurements the

video measurement set makes on the LCD display. Use the CONFIG menu to turn measurements ON or OFF. Measurements must be ON to appear in the MEAS list.

SIG ID. Press the signal identification button to display the name and location

of signals in the vertical interval and the source ID (when contained in the signal).

AVG. Press this toggle switch to turn signal averaging on and off. FREEZE. Press this toggle switch to turn the freeze feature on and off. When

FREEZE is turned on, all acquisition and measurement activity stops so that you can view intermediate measurement and signal ID results.

Arrow Buttons. Press the up (↑) or down (↓) arrow buttons to scroll through

various LCD displays. Press the left (←) and right (→) arrow buttons to change instrument parameters and to view measurement results on other video lines.

2–2

VM100 & VM101 Service Manual

Operating Information

Enter Button. Press the enter (↵) button to enter and exit the CONFIG

submenus and to control print and memory functions.

CONFIG. Press the configure button to access instrument configuration menus

and to view the instrument software version.

PRINT. Press the print button to print the current or saved measurement data or

to output results to a computer, using the RS-232 serial port. You must configure the RS-232 port for printing and select the print parameters before using the print function.

MEM. Press the memory button to save the current measurement and SIG ID

results in instrument memory and to access memory management selections including ERASE, REPLACE, VIEW, and RENAME.

LCD Display . The LCD display shows measurement readouts and menu

selections. Figure 2–2 shows examples of the text and symbols you will see on the LCD display. The symbols help you navigate quickly through the menu system using the arrow buttons and the enter button. Dots (…) following the menu name indicate that a menu has a submenu.

Shows submenu

Figure 2–2: LCD display characteristics

Arrow buttons Enter button

VM100 & VM101 Service Manual

2–3

Operating Information

Menus

The MEAS, SIG ID, MEM, PRINT, and CONFIG buttons allow access to additional selections or measurement results. Figures 2–3 and 2–4 show the menu structure of the video measurement set. The SIG ID menu is not shown because its contents depend upon the input signal characteristics.

2–4

Figure 2–3: The MEAS, MEM, and PRINT menus

VM100 & VM101 Service Manual

Operating Information

Figure 2–4: The CONFIG menu

VM100 & VM101 Service Manual

2–5

Operating Information

Rear Panel Connectors

There are seven connectors mounted on the video measurement set rear panel. Refer to Figure 2–5 for descriptions.

3 4

Figure 2–5: Rear panel connectors

AC Power Connector. The AC power connector is a standard AC plug receptacle

for 120 or 240 V

power mains. The plug is compatible with each available

power cord option.

ZERO CARRIER PULSE OUTPUT. The ZERO CARRIER PULSE OUTPUT

produces a reference pulse that triggers a demodulator. Signal amplitude is

1.5 V

when driving a 75 W load or TTL compatible when driving a high

p-p

impedance. This pulse is compatible with the trigger inputs on the following Tektronix Demodulators: DS1200, TDM5, 1450, 1340, and 1350.

EXT REF. This high-impedance, loop-through input (two BNC connectors)

accepts external reference signals of composite video or black burst (1 V Use this input if the video input has no sync information. The input is AC coupled and compensated for 75 W. It is not internally terminated.

INPUT. This high-impedance, loop-through input (two BNC connectors)

accepts video input signals for the video measurement set. The input is AC coupled and compensated for 75 W. It is not internally terminated.

RS232 Port. This nine-pin subminiature D-type female connector provides an

RS232 serial interface for printer and computer communication. The port also provides the interface for waveform the monitor control function.

p-p

2–6

VM100 & VM101 Service Manual

Operating Information

Power On Procedure

Configuration

To power on the video measurement set, connect it to the AC power source. There is no power switch.

The power-on sequence completes in approximately 10 seconds. After power on completes, check for the following conditions:

The LCD display shows the message No video present, or no lock possible (if no signals are connected to the rear panel INPUT connector).

The MEAS button indicator lights.

NOTE. The AVG button indicator lights at power on if the AVG feature was in use when AC power was last disconnected.

This section guides you through the configuration of each operating parameter. (No configuration is necessary for basic operation.) Refer to Table 2–1 for an overview of the parameters you can configure, the location of the configuration instructions, and the factory default values.

If you need more detailed information about the instrument features, refer to the VM100 & VM101 Video Measurement Sets User Manual (Tektronix part number 070-9522-XX).

NOTE. You cannot configure the hum frequency on the VM101. The default value is 50 Hz.

T able 2–1: Configuration parameters

Parameter Page Number Factory Default Value

MEASURE 2–8 SNR is ON

All other measurements are OFF

ZCR PULSE 2–9 VM100: Line 10

VM101: Line 7 SIG ID RANGE 2–10 VITS FULL FLD START 2–10 23 REF 2–11 Input HUM (VM100 only) 2–11 60HZ SNR FILTER 2–1 1 WEIGHTD RS232 2–1 1 for printing

2–12 for computer 2–13 for waveform monitor operation

Computer

VM100 & VM101 Service Manual

2–7

Operating Information

T able 2–1: Configuration parameters (cont.)

Parameter Factory Default V aluePage Number

PRINTER RS232

BAUD RATE STOP BITS PARITY FLOW CTL

COMPUTER

RS232 BAUD RATE STOP BITS PARITY FLOW CTL

1995 NOV 11 (Date)

YEAR MONTH DA Y

10:13:18AM (Time)

HOUR

MINUTE VIEW ANGLE 2–15 80 SW VER 2–15 Current software version CALIBRA TE 2–15 N/A

2–1 1

9600 1 NONE NONE

2–12

9600 1 NONE NONE

2–14 Today’s date

2–14 Current time

Use the following procedures to customize the operation of the video measurement set. Once you have configured the parameters, the video measurement set powers on as you configured it. Refer to page 2–1 for detailed descriptions of the front panel buttons or the LCD display.

NOTE. The video measurement set

uses the last setting that was saved for each

parameter if power is interrupted during configuration.

To exit the CONFIGURE menu at any time during these procedures, press the MEAS, SIG ID, MEM, or PRINT buttons.

Configure the Measurements. The video measurement set

performs a group of

measurements when you press the MEAS button. The display update rate depends upon the number of measurements made and the presence of valid input signals. You can customize this feature for your application by selecting only the measurements you need.

2–8

VM100 & VM101 Service Manual

Operating Information

Perform the following steps to choose measurements that will be performed when you press the MEAS button:

1. 2. 3. 4. 5.

Press the CONFIG button.

Select CONFIGURE MEASURE (default). Press the ↵ enter button.

Select the desired measurement. See list below.

Select ON or OFF. Repeat steps 3 and 4 to configure additional measurements.

The following measurements are available:

Differential Phase (DIFF PHASE) Differential Gain (DIFF GAIN) Chrominance-Luminance Delay (YC DELAY) Chrominance-Luminance Gain (YC GAIN) Signal-to-Noise Ratio (SNR WGT/FLAT) Frequency Response (FREQ FCC or AVG and FREQ DETAIL) Group Delay (GRPDLYmax and GRPDLYmin) Sync Amplitude (SYNC AMPL) Burst Amplitude (BURST AMPL)

Press the MEAS button to exit.

Configure the Zero Carrier Reference Pulse Trigger Output. The Zero Carrier Reference Pulse Trigger Output synchronizes a demodulator when you take hum measurements. You can configure the output to OFF or to any line from 10 – 20 (VM100) or 7 – 20 (VM101).

VM100 & VM101 Service Manual

Bar Amplitude (BAR AMPL) 2T K-Factor (2T K-FACTOR) Luminance Nonlinearity (LUM NON-LIN) Hum (HUM)

2–9

Operating Information

Perform the following steps to configure the Zero Carrier Reference Pulse Trigger Output:

1. 2. 3. 4.

Press the CONFIG button.

Select CONFIGURE ZCR PULSE.

Select OFF or a line number.

Press the MEAS button to exit.

Configure the Signal Identification Range. The SIG ID menu displays all of the test signals that are present in the video signal applied to the INPUT connector. You can configure the SIG ID range to match your system requirements (VITS or FULL).

Perform the following steps to configure the SIG ID range:

1. 2. 3. 4.

Press the CONFIG button.

Select SIG ID RANGE. Select VITS or FULL. Press the MEAS button

to exit.

NOTE. After you configure the signal identification range, the video measurement set reacquires the signal.

2–10

Configure the Full Field Start Line. You can configure the video line used for full

field start (valid only when the SIG ID range is FULL). With this feature you can view a specific video line within the active area.

Perform the following steps to configure the Full Field Start Line:

1. 2. 3.

Press the CONFIG button.

Select FULL FLD START.

Select 23 - 43 (VM100) or 23 – 39 (VM101).

Press the MEAS button to exit.

NOTE. After you configure the full field start line, the video measurement set reacquires the signal if FULL is selected.

VM100 & VM101 Service Manual

Operating Information

Configure the Reference. You can configure the video measurement set to use either an internally generated sync reference or a signal connected to the EXT REF rear panel input. For example, use an external reference if the video input has no sync information.

Perform the following steps to configure the Reference:

1. 2. 3.

Press the CONFIG button.

Select CONFIGURE REF.

Select INPUT or EXTERNAL.

Press the MEAS button to exit.

Configure the Hum Measurement (VM100 Only). You can configure the hum measurement to match your power line frequency (VM100 only). The video measurement set configuration must match your power line frequency to produce accurate hum measurement results.

Perform the following steps to configure the hum measurement:

1. 2. 3. 4.

Press the CONFIG button.

Select HUM. Select 50HZ or 60HZ. Press the MEAS button

to exit.

Configure the Signal-to-Noise Ratio Filter. The video measurement set provides weighted and flat filter selections for taking signal-to-noise measurements. You can configure the filter type needed for your application.

Perform the following steps to configure the SNR filter:

Configure for Printing. The video measurement set can drive a printer, computer, or waveform monitor using the RS232 serial port. To print the measurement results, you must configure the RS232 serial port for printer operation and select the parameters that match your printer.

VM100 & VM101 Service Manual

1. 2. 3. 4.

Press the CONFIG button.

Select SNR FILTER. Select WEIGHTD or

FLAT.

Press the MEAS button to exit.

2–11

Operating Information

Perform the following steps to configure the RS232 serial port to drive a printer:

1. 2. 3. 4.

Press the CONFIG button.

Select CONFIGURE RS232=.

Select PRINTER. Press the MEAS button

to exit.

NOTE. If the serial port is not configured for printing, the print function is disabled.

Refer to your printer manual to determine the settings for baud rate, stop bits, parity, and flow control.

Perform the following steps to configure the print parameters:

1. 2. 3. 4. 5.

Press the CONFIG button.

Select CONFIGURE PRINTER RS232. Press the ↵ enter button.

Choose the appropriate setting for the displayed parameter. See Table 2–2.

Select the next parameter. See Table 2–2. Repeat steps 3 and 4 for all parameters.

Press the MEAS button to exit.

T able 2–2: Print parameters

2–12

Parameter Settings

BAUD RA TE 1200, 2400, 9600, 19.2K STOP BITS 1 or 2 PARITY NONE, EVEN, ODD FLOW CTL NONE, XON/XOFF, HARDWARE

Configure for Computer Communications. The video measurement set can drive a computer, printer, or waveform monitor using the RS232 serial port. To send the measurement results to a computer or to set up for remote operation, you must configure the RS232 serial port for computer operation and select the parameters that match your computer interface.

VM100 & VM101 Service Manual

Operating Information

Perform the following steps to configure the RS232 port to drive a computer:

1. 2. 3.

Press the CONFIG button.

Select CONFIGURE RS232=.

Select COMPUTER. Press the MEAS button

to exit.

NOTE. Refer to your computer manual to determine the settings for baud rate, stop bits, parity, and flow control.

Perform the following steps to configure the computer interface parameters:

1. 2. 3. 4.

Press the CONFIG button.

Select CONFIGURE COMPUTER RS232. Press the ↵ enter button.

Choose the appropriate setting for the displayed parameter. See Table 2–3.

Select the next parameter. See Table 2–3. Repeat steps 3 and 4 for all parameters.

Press the MEAS button to exit.

NOTE. If COMPUTER was not selected at power on, you will experience a short delay when scrolling through the CONFIGURE RS232 menu choices.

T able 2–3: Computer interface parameters

Configure for Waveform Monitor Control Function. The video measurement set can

drive a computer, printer, or 1740A-series waveform monitor using the RS232 serial port. The waveform monitor control function allows you to view the waveform on a 1740A-series waveform monitor while the video measurement set measures the signal parameters.

VM100 & VM101 Service Manual

Parameter Settings

BAUD RA TE 1200, 2400, 9600, 19.2K STOP BITS 1 or 2 PARITY NONE, EVEN, ODD FLOW CTL NONE, XON/XOFF, HARDWARE

2–13

Operating Information

Perform the following steps to configure the RS232 port to drive a waveform monitor:

1. 2. 3. 4.

Press the CONFIG button.

Select CONFIGURE RS232=.

Select CONTROL. Press the MEAS button

to exit.

Configure the Date. The video measurement set keeps track of the date. Perform the following steps to change the date setting:

1. 2. 3. 4. 5.

Press the CONFIG button.

Select CONFIGURE <DATE>. Press the ↵ enter button.

Choose the appropriate setting for the displayed parameter. See Table 2–4.

Select the next parameter. See Table 2–4. Repeat steps 3 and 4 for all parameters.

Press the MEAS button to exit.

T able 2–4: Date parameters

Parameter Settings

YEAR 1990 through 2089 MONTH JAN through DEC DA Y 1 through 31

2–14

Configure the Time. The video measurement set keeps track of the time. Perform

the following steps to change the time setting:

1. 2. 3. 4. 5.

Press the CONFIG button.

Select CONFIGURE <TIME>. Press the ↵ enter button.

Choose the appropriate setting for the displayed parameter. See Table 2–5.

Select the next parameter. See Table 2–5. Repeat steps 3 and 4 for all parameters.

Press the MEAS button to exit.

VM100 & VM101 Service Manual

Operating Information

T able 2–5: Time parameters

Parameter Settings

HOUR 01AM to 12AM and 01PM to 12PM MINUTE 00 to 59

Adjust the LCD View Angle. You can adjust the viewing angle of the LCD display for the best readout with your lighting conditions. To change the viewing angle, place the video measurement set in the lighting conditions where you will use it and then perform the following steps:

1. 2. 3.

Press the CONFIG button.

Select CONFIGURE VIEW ANGLE.

Select 0 through 180 for best LCD display.

Press the MEAS button to exit.

Display the Software Version Number. You can view the software version number for the operating system installed in this video measurement set. Refer to this number if you need to report a software problem or order a software upgrade. The software version displayed here should correspond to the version number(s) printed on the title page of this manual.

Perform the following steps to view the software version number:

1. 2. 3.

Press the CONFIG button. Select CONFIGURE SW VER. Press the MEAS button to exit.

Calibration. If you inadvertently enter the CALIBRATE menu, use the following steps to exit the menu without changing internal video measurement set settings:

NOTE. Refer to the Adjustment Procedures section for test equipment require- ments and detailed adjustment instructions.

VM100 & VM101 Service Manual

1. 2.

Select PRESS ↵ TO ABORT CAL.

Press the ↵ enter button to exit the menu.

2–15

Operating Information

2–16

VM100 & VM101 Service Manual

Theory of Operation

This section describes the electrical operation of the video measurement set using the major circuit blocks or modules.

This section is divided into the following parts: H Logic Conventions describes how logic functions are discussed and

represented in this manual.

H Block Level Description describes circuit operation to the functional block

level.

H Detailed Circuit Description on page 3–3 describes circuit operation to the

circuit and component level.

Logic Conventions

This manual refers to digital circuits with standard logic symbols and terms. All logic functions use the positive-logic convention: the more positive of the two logic levels is the high state, and the more negative level is the low state. The specific voltages that constitute a high or low state may vary among the electronic devices.

Block Level Description

DC Restore

Sync Stripper

A back slash prefixed to the signal name (/RESET) indicates active-low signals. Signal names can be either active high, active low, or have both active-high and active-low states.

Refer to Figure 9–2, the detailed block diagram found on page 9–4, when reading the block-level description. The description explains the basic operation of each circuit block. If you need more detailed information, refer to the Detailed Circuit Description on page 3–3 and the component-level circuit diagrams found in the Diagrams section.

The DC Restore circuit selects AC or DC input coupling and clamps the backporch level of the video signal when AC coupling is active. To terminate the INPUT the user must install a 75 W device to the unused INPUT connector.

The Sync Stripper consists of a reference select circuit and three sync separators. The reference select circuit chooses either the INPUT video signal or an external signal for the sync reference. The sync separator uses the selected sync reference to generate composite, vertical, and horizontal sync signals.

VM100 & VM101 Service Manual

3–1

Theory of Operation

Gain, DC Offset, and

Filtering

Phase Lock Loop

Analog-to-Digital

Converter

Digital Signal Processor

Acquisition Control

The Gain, DC Offset, and Filtering block provides signal processing to the input video signal. The circuit selects one of three input filters, and also provides an anti-aliasing filter to remove unwanted signal components from the A/D Converter input. Under host processor control, the circuit provides fixed gain, variable gain, and variable DC offset for the video signal.

The Phase Lock Loop synchronizes signals within the video measurement set to a known reference. Either the video signal from the INPUT, or an external reference applied to the EXT REF input, can be used. The Phase Lock Loop locks to either the sync or burst signals.

The Analog-to-Digital (A/D) Converter converts the analog video signal into 10-bit digital words. The conversion rate is 8 times the subcarrier frequency.

The Digital Signal Processor (DSP) system is a coprocessor that makes rapid calculations using the acquired data. Processed waveform data from the DSP is available for use by the host processor.

The Acquisition Control stores data from the A/D Converter into waveform memory. It also controls the real-time aspects of acquisition such as bus arbitration phase lock operation, gain and DC offset settings.

Host Processor and

Memory

Remote Interface (RS232)

Front Panel

LCD Display

Power Supply

The host processor controls the main operating system functions including acquisition, front panel control, and the LCD display. The operating system stored in Flash EPROM can be upgraded through the RS232 port using an external PC controller.

The Remote Interface (RS232) drives the rear-panel RS-232 connector for remote operation.

The Front Panel contains a 13-switch keypad and 8 LED indicators. The host processor reads the front panel registers to detect switch closures, and writes to the registers to change the status of LED indicators.

The LCD Display provides displays of the measurement results, signal identification codes, and configuration parameters. The host processor provides signals to control the display and set the LCD viewing angle.

The Power Supply provides +12 V, –12 V, and +5 V.

3–2

VM100 & VM101 Service Manual

Detailed Circuit Description

This detailed circuit description explains the function of each major circuit. Use this description to help you isolate faults when troubleshooting. As you read the description, refer to the component-level circuit diagrams found in the Diagrams section.

Theory of Operation

DC Restore

The DC Restore circuit (diagram

) consists of the Video Input and Input

Amplifier. These circuits combine to perform the following functions:

H Select AC or DC input coupling H Clamp the backporch level of the video signal

Video Input. The video signal to be measured connects to loop-through INPUT connectors at either J30 or J31. The unused connector must be terminated with 75 W. Transistors Q2 and Q3 establish the coupling mode. When the AC/DC SEL line is high, C58 AC-couples the signal to amplifier U17. Acquisition

Control FPGA U99 (diagram

) controls the AC/DC SEL line. Switching

occurs to accommodate the requirements of signal measurement modes.

Input Amplifier. Input Amplifier U17 (diagram

) clamps the backporch level of

the video signal. Signal clamping determines the DC level measured at TP9. When the amplifier is operating, the DC level at TP9 is equal to the video backporch level at U17 pin-3, minus the voltage across sampling capacitor C13. An operational amplifier within U17 performs the subtraction using R60 to feed back the sample-and-hold output (buffered voltage on C13) to pin-1, the negative input of the operational amplifier.

The CLAMP_PLS signal (from U31, diagram backporch interval while U17 and C13 sample and hold the back porch level of

the incoming video. As a result, the backporch level of the clamped video is zero volts. The OFFSET signal from U30C (diagram negative input (pin 6) of the sample-and-hold amplifier to establish the DC level

of the clamped video. When switch U18A is closed, the DC restore circuit is disabled. The

DCREST_ON signal from U99 (diagram When the switch is closed, sampling capacitor C13 charges to the OFFSET

voltage. As a result only the OFFSET voltage is subtracted from the input video signal, under normal conditions the sum of the backporch level and the OFFSET voltage are subtracted.

VM100 & VM101 Service Manual

) goes low during the

) can then control the

) disables the DC Restore circuit.

3–3

Theory of Operation

Sync Stripper

The Sync Stripper (diagrams

and 2) consists of a Reference Select circuit

and three Sync Separators. The Reference Select circuit chooses either the internal video signal or an external signal for the sync reference. The Sync Separators use the selected sync reference to generate composite, vertical, and horizontal sync signals.

Reference Select. The selected sync reference signal controls video timing within the video measurement set. Video switch U14 selects either the INT VIDEO signal or an external signal connected to the EXT REF input. The INT/EXT

signal from U99 (diagram

) controls U14. When INT/EXT is high, the INT

VIDEO signal is selected.

Composite Sync Separator. The REF_VIDEO output from U16 drives pin-12 of composite sync separator U6. From this input, U6 generates the COMP_SYNC (horizontal and vertical composite synchronization) and BPSAMP (back porch sample) signals at pin-24 and pin-28, respectively.

An AGC (automatic gain control) circuit within U6 compensates for low- or high-gain input signals. Capacitor C55 samples and provides feedback of the sync amplitude for the AGC circuit.

Vertical Sync Separator. Active filter U85A filters the COMP_SYNC signal, and the combination of CR86, R172, and C213 provide envelope following. The filter integrates the broad pulses of the vertical interval so that during the vertical sync interval, the filter output goes lower than the output of the envelope

follower. For PAL signals, a low NTSC/PAL signal from U99 (diagram

)

increases the filter time constant by adding C24 to the filter.

Gain, DC Offset, and

3–4

Filtering

Comparator U85B compares the input and the output of the envelope follower. Buffer U87A buffers the output and shifts the logic level for CMOS compatibility. The resulting FIELD signal (at TP16) reflects the vertical sync rate.

Horizontal Sync Separator. U31 (diagram

) uses the COMP_SYNC signal to

generate the horizontal sync (HSYNC) signal. HSYNC is output on pin 8.

Figure 3–1 shows a simplified diagram of the Gain, DC Offset, and Filtering block. This block provides signal processing to the input video signal. It consists of the the Filter Select and Analog Processing circuits, which perform the following functions:

H Filter select H Gain H DC offset H Anti-aliasing filter

VM100 & VM101 Service Manual

Input amplifier Filter select Analog processing

Theory of Operation

Input

Flat

Lowpass

Chrom

Filter

switch

Filter 0 Filter 1 Filter 2

Figure 3–1: Simplified view of Gain, DC Offset, and Filtering block

Filter Select. Multiplexer U10 (diagram

to drive the A/D Converter: INT VIDEO (flat), CHROM (chrominance), and LUM (lowpass). Control lines FILTER0, FILTER1, and FILTER2 from U99

(diagram

) select the filter.

The flat filter output signal (INT VIDEO) is taken directly from pin-14 of input amplifier U17. Operational amplifiers U13 and U14 form a lowpass filter used to generate the LUM signal for the hum measurement. Buffer U20 and its surrounding components form a bandpass filter to generate the CHROM (chrominance) signal.

Gain and DC offset

Position

Vargain

Gain 0 Gain 1

Anti-aliasing

filter

Limit

) selects one of three filtered signals

T o A/D Converter

Analog Processing. The Analog Processing circuit controls gain and offset. The circuit also filters the video signal before routing it to the A/D Converter. A Gilbert gain cell within U5 provides variable gain, and switches within U5

control fixed gain. The VARGAIN signal from U29C (diagram

) controls

variable gain, while GAIN0 and GAIN1 from U99 control fixed gain. The Analog Controls circuit (U29D) generates the POSITION signal to rapidly

change the DC offset at the output of U5. The OFFSET signal (U17 pin-6) also adjusts DC offset but has a slower response time because it serves as the reference for the DC Restore circuit.

After U5 sets gain and DC offset, buffer U9 converts the current output signal to a voltage. The signal is then applied to an anti-aliasing filter consisting of inductors L11, L12, and the surrounding components. The filter removes signal components whose frequencies exceed 4-times the subcarrier frequency (the Nyquist frequency at the 8-times subcarrier frequency sampling rate of the A/D Converter).

The LIMIT signal generated by U84 provides status information to the Acquisition Control circuit (diagram 4). If the video signal limits due to low or high signal amplitude, the LIMIT signal goes high.

VM100 & VM101 Service Manual

3–5

Theory of Operation

Phase Lock Loop

The Phase Lock Loop circuit synchronizes signals within the video measurement set to a known reference. Either the video signal from the INPUT, or an external reference applied to the EXT REF input can be used. The Phase Lock Loop contains circuits for locking to the sync and burst signals.

The Phase Lock Loop circuits use a common voltage-controlled crystal oscillator (VCXO). They also contain phase detectors, a counter/divider circuit for synthesizing burst, h-sync, and a multiplexer for selecting either subcarrier burst phase error or horizontal synchronization phase error signals.

VCXO. VCXO Y1 (diagram

) is the controlled oscillator within the loops. The

crystal frequency is 28.63636 MHz for the VM100 and 35.46895 MHz for the VM101. Control line SYNC/BURST from U31 selects which error voltage source (sync or burst) will control the VCXO through switch U120.

The output of the VCXO is a 50% "5% duty cycle square wave at 8-times the subcarrier frequency. Comparator U116 buffers the VCXO output to create both positive (8FSC_IN) and negative (/8FSC_IN) polarities with very low time skew.

Buffer U12A and comparators U113C and U113D form a window comparator that senses when a loop is unable to achieve lock. When the error voltage at TP19 reaches either the upper (+4 V) or lower (+1 V) limit, U113C or U113D sets the /PLL RANGE signal low. When this occurs, U31 attempts to close the loop. If unable to reestablish a locked loop, U31 asserts the /UNLOCKED line to alert the acquisition system of the unlocked condition.

U31 generates miscellanious video line-based timing signals for use during acquisition. It also generates the 2 MHz square wave DSP_RCK signal. DSP

U48 (diagram

) uses the DSP_RCK signal as its phase-lock loop input. The

DSP clock has a known frequency relationship to the sample (A/DC) clock when it locks to the DSP_RCK signal.

Sync-Locked Loop. Error amplifiers U26A and U26B form the horizontal synchronization signal (h-sync) phase detector for the Sync-Locked Loop. When in sync locked mode, U31 sets the SYNC/BURST signal high to control the VCXO from U26B pin-7.

Within U31, the 8FSC_IN signal from U116 is divided to one-half the h-sync frequency. The HSYNC signal is also divided by two within U31. Both signals are applied to a phase detector that produces outputs on pin-4 and pin-5 to drive error amplifier U26A.

Burst Locked Loop. The Gilbert multiplier section of U118 serves as the burst phase detector for the Burst Locked Loop. U118 detects errors between the REF_VIDEO signal and the synthesized FSC burst frequency signal from U31.

3–6

VM100 & VM101 Service Manual

Theory of Operation

After level shifting and buffering by Q7, Q6 and U12B, the phase error signal passes through switch U120 to control the VCXO. U31 sets the SYNC/BURST signal low to close the switch.

U31 generates the BP_GATE signal by counting the 8FSC_IN signal edges with reference to HSYNC. The BP_GATE signal gates the burst phase detector through gates U119A and U119B. To achieve lock, U31 divides the 8FSC_IN signal from the VCXO to the subcarrier frequency, producing the FSC and /FSC signals which are compared to REF_VIDEO by phase detector U118.

A/D Converter

A/D Converter U22 (diagram 3) converts the VIDEO signal into 10-bit digital words. The conversion rate is 8-times the subcarrier frequency, controlled by the 8FSC signal. During acquisition, Aquisition Control FPGA U99 (diagram

)

enables tri-state buffers U38 and U39 to drive the DSP data bus with the A/D Converter output. The A/D Converter is part of the Acquisition and DSP system within the video measurement set. Figure 3–2 shows a simplified view of the system.

VM100 & VM101 Service Manual

3–7

Theory of Operation

U43, U44, U46

8FSC

Video

U22

A/D

Conv

To Host

Processor

ADC D0-9

U35, U38

Buffer

U57 U96 U97

To Host

Processor

D0-D7

Memory

Y/Acq

AC A0-15

Host bus

buffers

AC D0-23

X/Prgm

Memory

Host bus

buffers

U48 U99

DSP PC0-8 DAC D0-7

Misc

control

signal

U93 U94 U95

U34, U35, U36, U37

Acq Memory address

generator

U27, U28

Analog control

FPGADSP

Misc HW control

AC PA0-15

Figure 3–2: Acquisition and DSP system

Digital Signal Processor

(DSP)

The Digital Signal Processor (DSP) system is a coprocessor that makes rapid calculations using the acquired data. It follows instructions provided by the host processor to process the waveform data, and to make the data available to the host processor.

The DSP system consists of the following circuits:

H Acquisition Memory H X/Program Memory H Digital Signal Processor (DSP)

Acquisition Memory. The Acquisition Memory (U57, U96, and U97 on diagram

) stores the signal amplitude (Y-axis) data output by A/D Converter U22. The

A/D Converter writes data words to Acquisition Memory through tri-state buffers U38 and U39. The host processor also accesses Acquisition Memory

U41, U42

3–8

VM100 & VM101 Service Manual

Theory of Operation

through tri-state transceivers U41, U42, U43, U44, and U46. The memory is 24-bits wide and 64K words deep. It resides in the native Y-memory space of DSP U48 and the host processor.

X/Program Memory. The X/Program Memory (U93, U94, U95 on diagram

)

stores the DSP program provided by the host processor and the address locations (X-axis) of the acquired signal data. The host processor also accesses Acquisition Memory through tri-state transceivers U41, U42, U43, U44, and U46. The X/Program memory is 24-bits wide and 64K words deep.

Digital Signal Processor (DSP). Digital Signal Processor (DSP) U48 (located on diagram

) is a coprocessor that makes rapid calculations using the acquired

data. The DSP communicates directly with the host processor through its host port located in host memory space. The DSP also communicates with the host processor by writing measurement results to X-memory and signalling the host

to read it. Acquisition Control FPGA U99 (diagram

) controls bus arbitration,

a process that removes the DSP from the bus during acquisition and host access. The host processor loads the DSP program into DSP program memory (U93,

U94, and U95). After the program is loaded, it begins with initialization which includes the following tasks:

H Program the internal phase lock loop (U31 on diagram

DSP_RCK signal. (When locked, LED DS1 on diagram

) to lock to the

turns on.)

H Copy internal X-constant and Y-constant data from external X-memory and

Y-memory, if needed

After initialization, the DSP waits for host commands through the host port.

Acquisition Control

Acquisition Control FPGA U99 (diagram Converter into waveform memory. It also controls the real-time aspects of

acquisition including the following:

H Implement bus arbitration between the DSP, host processor, and A/D

H Control settings for the Gain, DC Offset, and Filtering block and the Phase

H Check the status of the Gain, DC Offset, and Filtering block and the Phase

Acquisition Control FPGA U99 counts video lines and fields based on the HSYNC and FIELD signals from the Sync Stripper circuit. The host processor programs registers within U99 that control the following parameters:

VM100 & VM101 Service Manual

Converter

Lock Loop

) stores data from the A/D

3–9

Theory of Operation

H Line and field where acquisition will start H Number of lines to acquire H Acquisition of sync tip for the hum measurement

Host Processor and

/RESET

Memory

IRQ

U79

Reset

H PULSE

The host processor (diagram

) controls the main operating system functions

including acquisition, front panel functions, and the LCD display. Figure 3–3 shows a simplified view of the system.

U62, U63

/RST

U80

Host

Processor

A0-16

A0-23

U61

Boot

ROM

U76, U77, U78

Address

buffer

D8-15

BA0-23

BA1-19

Data

buffer

U101, U102

Flash

EPROM

U71, U72, U103, U108

BD0-15

BD0-15D0-15

3–10

BA0-17

RAM

U100

BA0-14

NVRAM

BD0-15

BD8-15

Figure 3–3: Host processor and memory system

Host processor U80 receives initial instructions from boot ROM U61, which connects directly to the address bus. All other memory and peripheral devices reside on one of two external buses:

VM100 & VM101 Service Manual

Theory of Operation

H System memory bus, which includes SRAM (U71, U72, U103, and U108),

NVRAM (U100), and Flash EPROM (U101 and U102)

H DSP bus, which includes DSP U48, Acquisition Control FPGA U99,

Acquisition Memory, and X/Program Memory

Reset circuit U79 (diagram

) synchronizes the system reset function and

ensures that the host processor powers up to a known state. The +5 V supply connects to U79 pin-7. When power is turned on, U79 holds the /RST signal on pin-5 low until the +5 V supply reaches a safe operating level. The /RST signal controls the host processor reset (U80 pin-69). If the +5 V supply drops below normal limits, U79 asserts the /RST line low so the host processor can initiate the power-down sequence. Buffer U66A routes the /RESET signal to DSP U48, Acquisition Control FPGA U99, and RS-232 DUART IC U115.

The host processor performs system diagnostics during the power-on sequence. When power is turned on, the reset circuit (U79) ensures that the host processor powers up to a known state. The host processor then runs the program in boot ROM U61 to execute the diagnostics as shown in Table 3–1.

T able 3–1: Power-on diagnostics

Diagnostic Test Indication of Successful Test

Initialize the memory mapped I/O and bus control logic (program the internal chip select logic and interrupts)

Checksum test for boot ROM U61 LED DS2 blinks one time Host Processor enables the external data and address

buses (U62, U63, U66, U70, U73, U76, U77, U78)

LED DS2 blinks one time

LED DS2 blinks two times

Remote Interface (RS232)

The host processor communicates with the RS-232 port through DUART IC U115 and RS232 transceiver U112 (diagram 8-bit parallel data from the host processor to serial data for transmission. It also

converts serial data received from the remote interface to 8-bit parallel data. In addition to buffering the data, DUART IC U115 generates an interrupt on

IRQ5 whenever data is received or transmitted. Transceiver U112 converts signals to the levels required for internal and external devices. DUART IC U115 requires CMOS levels and external devices require RS232 logic levels.

VM100 & VM101 Service Manual

Host Processor testing the system SRAM U71, U72, U103, U108 (excluding acquisition and DSP memory)

The program then switches to Flash EPROM memory (U101 and U102) for normal operation.

LED DS2 blinks three times

LCD Display is enabled; LED DS2 blinks five times

). DUART IC U115 converts

3–11

Theory of Operation

Rotary switch S1 controls the RS232 serial interface pin selection for the TX (Transmit Data) and RX (Receive Data) lines. The switch is set at the factory to the clockwise position (pointing to DEFAULT label on the circuit board).

Front Panel

LCD Display

Power Supply

The front panel board (A1) contains a 13-switch keypad and eight LED indicators. The host processor reads and writes the control data through a two-way serial bus. Once every 20 ms, the host processor latches the keypad data

into shift registers U2 and U3 (diagram

). The host processor then clocks U2

and U3 to generate the serial FPMISO signal, which it reads to determine the switch status. Each closed switch produces a low bit within the serial FPMISO string. When LED status changes are required, the host processor loads shift register U1 with an 8-bit control string (BMOSI).

Buffer U74 (diagram

) routes the clock and serial data to the front panel

board (A1). Decoder U75 performs the address decoding for the serial bus.

The LCD board (A4) contains the LCD display (diagram

). Built-in drivers

on the board connect to the microprocessor bus as an 8-bit port. Shift register U122 lengthens and inverts the chip select signals for compatibility with the

LCD. The LCD_ANGLE signal from U30D (diagram

) controls the LCD

viewing angle as viewed from top to bottom.

The power supply board (A3) supplies +12 V, –12 V, and +5 V to the main board (A2). Voltage regulators on the main board (diagram

) post-regulate the

+12 V supply to +8 V, and the –12 V supply to –8 V and –5 V.

3–12

A switching regulator consisting of U124 and Q123 provides greater efficiency for the –5 V supply. Switching regulator U124 turns on FET pair Q123 often enough to charge C293 to an average of –5 V. This forces VFB at pin-2 to equal the VREF level at pin-8. A second-order filter formed by L21 and C290 passes the average (low frequency) value to pin-2 (VFB) of U124 through amplifier Q9 and resistors R365 and R366. L20 and C289 provide additional filtering.

VM100 & VM101 Service Manual

Performance Verification

This section contains information needed to test the performance of the video measurement set. The procedure tests each characteristic that is designated as checked (REQ) in Specifications.

The Performance Verification Procedure is divided into the following parts: H General Information on page 4–1 provides basic information you need

before performing the tests

H Prerequisites on page 4–2 describes conditions that must be met before

performing the tests

H Equipment Required on page 4–2 lists the test equipment you need to

perform the tests

H Test Record on page 4–3 provides a way to record the test results H Performance Verification Procedure on page 4–4 provides the procedures

needed to test the video measurement set

General Information

Purpose

Test Interval

Read the following information before performing the Performance Verification Procedure.

This procedure verifies that the video measurement set performance is in conformance with the specifications that are designated as checked (REQ) in Specifications.

Generally, you should perform these procedures once a year to ensure that the video measurement set is operating within specified parameters. In addition, perform the procedures after module replacement.

VM100 & VM101 Service Manual

4–1

Performance Verification

Prerequisites

The tests in this section comprise a valid confirmation of performance and functionality when the following requirements are met:

H The video measurement set was last adjusted at an ambient temperature

H For operating temperatures below +20_ C, you must allow a warmup period

H The cabinet is installed on the video measurement set. H The video measurement set is in an environment within the limits described

Equipment Requirements

between +20_ C and +30_ C and is operating at an ambient temperature between 0_ C and +50_ C.

of 25 minutes (no warmup time is needed for temperatures at or above +20_ C).

in Table 1–6 on page 1–5.

These procedures use external, traceable signal sources to directly test characteristics that are designated as (REQ) in Specifications. Table 4–1 shows the required test equipment.

T able 4–1: Test Equipment

Item Description Minimum Requirements Example

Test Signal Generator Amplitude accuracy: "0.5%

Differential phase: "0.3° Differential gain: "0.3% K-factor: "0.3% Chroma delay: 2.5 ns Chroma gain: "0.5% Luminance nonlinearity: "0.4% Group delay: v3 ns Frequency response: "0.05 dB from

0.5 – 4.8 MHz, "0.06 dB at 5.8 MHz

Cable, Precision 75 W Coaxial

Termination, 75 W 75 W, male BNC connector Tektronix part number

75 W, 42 in, male-to-male BNC connectors Tektronix part number

Tektronix TG 2000 with the AVG module

012–0074–00

01 1–0102–01

4–2

VM100 & VM101 Service Manual

Test Record

Performance Verification

Use this form to record the results of the Performance Verification Procedure for the video measurement set.

Serial Number Procedure Performed By Date

Procedure Step Requirement Test Result

Differential Phase ±1.0° Differential Gain ±2.0% Sync Amplitude ±1% Burst Amplitude ±1% Bar Amplitude ±1% 2T K-Factor Chroma-Luma Delay ±10 ns Chroma-Luma Gain ±2.0% Luminance Nonlinearity ±1% Max Group Delay 0 to 20 ns Min Group Delay 0 to –20 ns Frequency Response

FREQ FLAG ±1% FREQ #1 ±0.2 dB FREQ #2 ±0.2 dB FREQ #3 ±0.2 dB FREQ #4 ±0.2 dB FREQ #5 ±0.2 dB FREQ #6 ±0.2 dB

≤2 %

VM100 & VM101 Service Manual

4–3

Performance Verification

Performance V erification Procedure

This section provides the procedures needed to test the video measurement set. If you are not familiar with the operation of the video measurement set, read the Operating Information section before proceeding.

These procedures test the NTSC (VM100) and PAL (VM101) versions of the video measurement set. When the requirements and measurement results are not the same for the VM100 and VM101, the procedure will specify the differences.

NOTE. When instructed, verify that the signal displayed on the video measurement set is within the specified percentage of the generator signal.

Initial Setup

Configure the Video

Measurement Set

Perform the following steps to power on the equipment:

1. Connect the output of the test signal generator to the rear-panel input of the

video measurement set, as shown in Figure 4–1. If you are using a TG 2000 generator, configure the AVG1 module for a composite output on all channels and connect the cable to any of the AVG1 outputs.

2. Power on the test signal generator and the video measurement set. Allow at

least a 15 minute warm-up period before proceeding.

TV signal generator

VM10X (rear)

Output

BNC cable

Input

75 W

Figure 4–1: Initial setup for the PV procedure

Perform the following steps to select measurements the video measurement set will perform during the Performance Verification Procedure:

4–4

1. On the video measurement set, press the AVG button to turn averaging on

(LED is illuminated).

2. Press the CONFIG button.

3. Press the ↵ enter button to enter the CONFIG MEAS submenu.

VM100 & VM101 Service Manual

Performance Verification

NOTE. All measurements must be configured to ON except for SNR and HUM.

4. Press the ↓ arrow button to scroll through the CONFIG MEAS submenu. Press the → arrow button to turn off the SNR and HUM measurements.

5. Press the MEAS button to exit the menu.

Signal Identification Test

Differential Phase Test

Differential Gain Test

Perform the following steps to test the signal identification feature:

1. On the video measurement set, press the SIG ID button. Verify that the LED in the center of the button is illuminated.

2. Press the ↓ arrow button to scroll through the SIG ID menu. Verify that all of the signal names and locations match the VITS signals generated by the test signal generator.

Perform the following steps to test the differential phase measurement accuracy:

1. Set the test signal generator to produce the following signal:

H VM100: NTC7 Composite signal H VM101: CCIR 330 signal

2. On the video measurement set, press the MEAS button and check that the LED in the center of the button is illuminated.

3. Verify that the displayed differential phase is within ±1.0°.

Perform the following steps to test the differential gain measurement accuracy:

1. Set the test signal generator to produce the following signal:

2. On the video measurement set, press the ↓ arrow button to scroll to the

3. Verify that the displayed differential gain is within ±2.0%.

Sync Amplitude Test

VM100 & VM101 Service Manual

Perform the following steps to test the sync amplitude measurement accuracy:

1. Set the test signal generator to produce the following signal:

H VM100: NTC7 Composite signal H VM101: CCIR 330 signal

DIFF GAIN measurement screen.

H VM100: NTC7 Composite signal H VM101: CCIR 330 signal

4–5

Performance Verification

2. On the video measurement set, press the ↓ arrow button to scroll to the

SYNC AMPL measurement screen.

3. Verify that the displayed sync amplitude is within ±1%.

Burst Amplitude Test

Bar Amplitude Test

Perform the following steps to test the burst amplitude measurement accuracy:

1. Set the test signal generator to produce the following signal:

H VM100: NTC7 Composite signal H VM101: CCIR 330 signal

2. On the video measurement set, press the ↓ arrow button to scroll to the

BURST AMPL measurement screen.

3. Verify that the displayed burst amplitude is within ±1%.

Perform the following steps to test the bar amplitude measurement accuracy:

1. Set the test signal generator to produce the following signal:

H VM100: NTC7 Composite signal H VM101: CCIR 330 signal

2. On the video measurement set, press the ↓ arrow button to scroll to the

BAR AMPL measurement screen.

3. Verify that the displayed bar amplitude is within ±1%.

2T K-factor Test

Chrominance-to-

Luminance Delay Test

4–6

Perform the following steps to test the 2T K-factor measurement accuracy:

1. Set the test signal generator to produce the following signal:

H VM100: NTC7 Composite signal H VM101: CCIR 330 signal

2. On the video measurement set, press the ↓ arrow button to scroll to the

2 T K-FACTOR measurement screen.

3. Verify that the displayed measurement is ≤2%.

Perform the following steps to test the chrominance-to-luminance delay measurement accuracy:

1. Set the test signal generator to produce the following signal:

H VM100: NTC7 Composite signal H VM101: CCIR 17 signal

VM100 & VM101 Service Manual

Performance Verification

2. On the video measurement set, press the ↓ arrow button to scroll to the YC DELAY measurement screen.

3. Verify that the displayed delay is within ±10 ns.

Chrominance-to-

Luminance Gain Test

Luminance Nonlinearity

Test

Perform the following steps to test the chrominance-to-luminance gain measurement accuracy:

1. Set the test signal generator to produce the following signal:

H VM100: NTC7 Composite signal H VM101: CCIR 17 signal

2. On the video measurement set, press the ↓ arrow button to scroll to the YC GAIN measurement screen.

3. Verify that the displayed chrominance-to-luminance gain is within ±2.0%.

Perform the following steps to test the luminance nonlinearity measurement accuracy:

1. Set the test signal generator to produce a Luminance 5 Step signal.

2. On the video measurement set, press the ↓ arrow button to scroll to the

LUM NON-LIN measurement screen.

3. Verify that the displayed luminance linearity is within ±1%.

Group Delay Test

VM100 & VM101 Service Manual

Perform the following steps to test the group delay measurement accuracy:

1. Set the test signal generator to produce the following signal:

2. On the video measurement set, press the ↓ arrow button to scroll to the

3. Verify that the displayed max group delay is 0 to 20 ns.

4. Press the ↓ arrow button to scroll to the GRPDLYmin measurement screen.

5. Verify that the displayed min group delay is 0 to –20 ns.



H VM100: Philips H VM101: Philips

GRPDLYmax measurement screen.

GCR or Sinx/x signal



GCR or Sinx/x signal

4–7

Performance Verification

NOTE. If your TV test signal generator does not provide measurements in dB, use the following equation to convert the signal generator’s frequency packet amplitude to dB before proceeding to the Frequency Response test:

Frequency Response Test

Characterized pkt (dB) =

pkt (charact) is the amplitude of a specific packet % flag is the size of the packet relative to the flag element (typically 100%) flag (charact) is the amplitude of the flag element of multiburst

Perform the following steps to test the frequency response measurement accuracy:

1. Set the test signal generator to produce the following signal:

H VM100: multiburst signal H VM101: CCIR18 signal

2. On the video measurement set, press the ↓ arrow button to scroll to the

FREQ FLAG measurement screen.

3. Verify that the displayed amplitude is within ±1%.

4. Press the ↓ arrow button to scroll to the FREQ #1 measurement screen.

20 log

[pkt (charact)] x [%flag100%]

[flag (charact)]

5. Verify that the displayed amplitude is within ±0.2 dB.

6. Repeat steps 4 and 5 for the FREQ #2, FREQ #3, FREQ #4, FREQ #5, and

FREQ #6 measurement results.

4–8

VM100 & VM101 Service Manual

Adjustment Procedures

This section contains information needed to adjust the video measurement set. The CONFIGURE CALIBRATION menu that you access by pressing the CONFIG button contains built-in adjustment instructions.

General Information

The Adjustment Procedures are divided into the following sections: H Requirements for Performance provides general information about adjusting

the video measurement set

H Equipment Required on page 5–2 provides a list of equipment required to

perform the adjustments

H Adjustment Procedure on page 5–3 provides a summary of the built-in

adjustment procedure, and illustrations that show the test equipment setups

Purpose

Adjustment Interval

This procedure returns the video measurement set to conformance with the warranted characteristics listed in the Specifications section. The procedure can also be used to optimize the performance of the video measurement set.

As a general rule, these adjustments should be done once a year. In addition, you may need to perform the adjustment procedure after the removal or replacement of a module, depending on the module serviced. See Table 5–1 for details.

T able 5–1: Adjustments after repair

Module Replaced Adjustment Required

front panel board (A1) No main board (A2) Yes power supply board (A3) Yes LCD board (A4) No

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5–1

Adjustment Procedures

Requirements

Before performing the Adjustment Procedures, meet the following requirements.

Personnel

Warmup Period

Access

Required Test Equipment

Only trained service technicians should perform this procedure.

The video measurement set requires a 15-minute warmup time in a +20_ C to +30_ C environment before it is adjusted.

NOTE. Adjustments performed before the operating temperature has stabilized may cause errors in performance.

Do not remove the top cover to perform this procedure.

Table 5–2 lists the test equipment required to adjust the video measurement set.

T able 5–2: Required test equipment

Item Description Minimum Requirements Example

Test Signal Generator Produces NTSC (for VM100) or PAL (for

VM101) signal with burst and sync. Accuracy equivalent to the Tektronix TG 2000.

Tektronix TG 2000 with the AVG module

5–2

Voltage Reference Amplitude error: Within 2 mV for all

settings from –715 mV to +715 mV , including 0 V

Cable, Precision 75 W Coaxial (2 required)

Termination, 75 W 75 W, male BNC connector Tektronix part number

Connector, Dual-Banana Female BNC to dual banana Tektronix part number

75 W, 42 in, male-to-male BNC connectors Tektronix part number

Data Precision 8200

012–0074–00

01 1–0102–01

103–0090–00

VM100 & VM101 Service Manual

Adjustment Procedure

Adjustment Procedures

This section explains how to adjust the video measurement set.

NOTE. Rotary switch A2S1 sets the proper signal connections to the RS-232 serial interface. Be sure the switch is set to the fully clockwise position (pointing to DEFAULT label on the circuit board).

Interrupting the

Adjustments

Performing the

Adjustments

You can exit the adjustment procedure at any step by pressing the ↵ enter button. If you exit the adjustment procedure before it completes, the video measurement set displays the message “CAL & MEAS INVALID.” Under these conditions, the video measurement set could display inaccurate measurement results.

NOTE. To avoid inaccurate measurement results, do not perform measurements when the message, “CAL & MEAS INVALID,” is displayed.

To restore the previously saved calibration data, turn off the video measurement set and then turn it on again.

When using the built-in adjustment procedure, you will not manually adjust the circuits. Instead, the video measurement set adjusts its internal circuits using external DC voltages you provide in response to prompts on the LCD display. Your role is to connect the test signals and to instruct the video measurement set to continue. Upon successful completion of the adjustment procedure, the video measurement set automatically loads the new calibration data into memory.

Perform the following steps to adjust the video measurement set:

1. Connect the equipment as shown in Figure 5–1.

NOTE. Do not connect a 75 W terminator to the INPUT connector unless your voltage reference can supply more than 10 mA.

If the voltage reference output is current-limited, the terminator may attenuate the output voltage, causing the adjustment procedure to fail.

VM100 & VM101 Service Manual

5–3

Adjustment Procedures

TV signal generator

VM10X (rear)

BNC

cable

Ext Ref Input

BNC cable

75 W

Voltage reference

+ –

Output

Dual banana to

BNC adapter

Figure 5–1: Equipment setup for the adjustment procedure

2. Set the test signal generator to produce a signal that has the correct format

for the video measurement set (VM100 is NTSC; VM101 is PAL).

NOTE. Use any video signal having the correct format (NTSC or PAL) that contains burst and sync.

If you do not connect a video signal, or the video signal is the wrong format, the video measurement set displays the message, “APPLY VIDEO TO EXT.” Under these conditions you will not be able to continue the adjustment procedure.

3. On the video measurement set, press the CONFIG button.

4. Press the ↑ arrow button to select “CONFIGURE CALIBRATION.”

5. Press the ↵ enter button to select “CONFIG–-CAL PRESS ↵ TO BEGIN

CAL.”

5–4

NOTE. To exit the procedure without changing any internal settings, press the ↑ or ↓ arrow key to select “PRESS ↵ TO ABORT CAL.”

6. Press the ↵ enter button to begin the procedure.

VM100 & VM101 Service Manual

Adjustment Procedures

7. To adjust the video measurement set, follow the on-screen prompts until the message, “CAL COMPLETE,” is displayed. Table 5–3 provides a summary of the adjustment steps.

T able 5–3: Adjustment steps

Step Number Signal Required and Action

1 2 3 4 5 6 7 8 9 10 11 12

Apply 0 V to INPUT and press ↓. Apply video signal to EXT REF and press ↓. Apply –714.3 mV to INPUT and press ↓. Apply +714.3 mV to INPUT and press ↓. Apply 0 V to INPUT and press ↓. Apply +714.3 mV to INPUT and press ↓. Apply +357.1 mV to INPUT and press ↓. Apply +142.9 mV to INPUT and press ↓. Apply +71.4 mV to INPUT and press ↓. Apply 0 V to INPUT and press ↓. Apply +714.3 mV to INPUT and press ↓. Apply 0 V to INPUT and press ↓.

8. Disconnect the equipment from the video measurement set.

VM100 & VM101 Service Manual

5–5

Adjustment Procedures

5–6

VM100 & VM101 Service Manual

Maintenance

Preventing ESD

This chapter contains the information needed to do periodic and corrective maintenance on the video measurement set. The following sections are included:

H The Maintenance section provides general information on preventing

damage to internal modules when doing maintenance, lithium battery warnings and disposal instructions, and procedures for inspecting the video measurement set and cleaning its external and internal modules.

H The Removal and Installation Procedures (page 6–7) provide procedures for

the removal and installation of modules.

H Troubleshooting (page 6–17) provides information for isolating failed

modules. Included are power supply parameters, and examples of waveforms measured at key test points within the video measurement set.

H Repackaging Instructions (page 6–33) provides packaging information for

shipment or storage.

When performing any service that requires internal access to the video measurement set, 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 video measurement set.

Minimize handling of static-sensitive modules.

Transport and store static-sensitive modules in their static protected containers or on a metal rail. Label any package that contains static-sensitive modules.

Discharge the static voltage from your body by wearing a grounded antistatic wrist strap while handling these modules. Do service of static-sensitive modules only at a static-free work station.

Nothing capable of generating or holding a static charge should be allowed on the work station surface.

Handle circuit boards by the edges when possible. Do not slide the modules over any surface.

VM100 & VM101 Service Manual

6–1

Maintenance

Avoid handling modules in areas that have a floor or work-surface covering capable of generating a static charge.

This instrument contains electrical components that can be damaged by static discharge. See Table 6–1 for the relative susceptibility of various classes of semiconductors. Static voltages of 1 kV to 30 kV can occur in unprotected environments.

T able 6–1: Relative susceptibility to static discharge damage

Semiconductor Classes Relative Susceptibility Levels

MOS or CMOS microcircuits or discretes, or linear microcircuitswith MOS inputs (most sensitive)

ECL 200 to 500 V Schottky signal diodes 250 V Schottky TTL 500 V High frequency bipolar transistors 400 to 600 V JFET devices 600 to 800 V Linear microcircuits 400 to 1000 V Low power Schottky TTL 900 V TTL (Least Sensitive) 1200 V

100 to 500 V

Battery Disposal

Dispose of lithium batteries according to local, state, and federal regulations.

WARNING. To avoid personal injury, observe the proper procedures for handling lithium batteries.

Improper handling can cause fire, explosion, or severe burns. Do not recharge, crush, disassemble, heat above 100° C (212° F), incinerate, or

expose the battery to water.

The video measurement set contains one lithium battery, A2U100, located on the main board (A2). Battery replacement is accomplished by replacing A2U100 or by installing a new main board (A2). Read the following information before replacing the battery. See lithium battery on page 6–16 for replacement instructions.

6–2

VM100 & VM101 Service Manual

Inspection and Cleaning

Maintenance

Inspection and cleaning are done as preventive maintenance. Preventive maintenance, when done regularly, may prevent malfunctions and enhance reliability.

Preventive maintenance consists of visually inspecting and cleaning the video measurement set, and using general care when operating it.

How often to do maintenance depends on the severity of the environment in which the video measurement set is used. A proper time to perform preventive maintenance is just before adjustment of the video measurement set.

General Care

Inspection and Cleaning

Procedures

The top cover keeps dust out of the video measurement set and should be in place during normal operation.

Inspect and clean the video measurement set 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 video measurement set failure, especially under high-humidity conditions.

CAUTION. Avoid the use of chemical cleaning agents that might damage the plastics and external labels used in the video measurement set.

Use a cloth dampened with water to clean external surfaces. Use a cloth dampend with a 75% isopropyl alcohol solution to clean internal

surfaces. Before using any other type of cleaner, consult a Tektronix Service Center or

technical representative.

that could cause a

Inspection — Exterior. Inspect the outside of the video measurement set for damage, wear, and missing parts. Use Table 6–2 as a guide. Instruments that 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 video measurement set.

VM100 & VM101 Service Manual

6–3

Maintenance

T able 6–2: External inspection check list

Item Inspect For Repair Action

Front panel and top cover

Front panel buttons Broken or cracked key caps. Replace defective modules.

Cracks, scratches, deformations, missing or damaged retainer screws.

Replace defective or missing modules.

Rear connectors Cracked or broken shells, dam-

aged or missing contacts. Dirt in connectors.

Accessories Missing items or parts of items,

bent pins, broken or frayed cables, and damaged connectors.

Replace defective modules. Clear or wash out dirt.

Replace damaged or missing items, frayed cables, and defective modules.

CAUTION. To prevent damage to electrical components from moisture during external cleaning, use only enough liquid to dampen the cloth or applicator.

Cleaning Procedure — Exterior. To clean the video measurement set exterior, perform the following steps:

1. Remove loose dust on the outside with a lint-free cloth.

2. Remove remaining dirt with a lint free cloth dampened with water.

Inspection — Interior. Remove the top cover (see page 6–8) to access the inside of the video measurement set for inspection and cleaning.

Inspect the internal portions for damage and wear using Table 6–3 as a guide. Defects found should be repaired immediately. If any electrical module is replaced, check Table 5–1 on page 5–1 to determine if you need to adjust the video measurement set.

6–4

T able 6–3: Internal inspection check list

Item Inspect For Repair Action

Circuit boards Loose, broken, or corroded

solder connections. Burned circuit boards. Burned, broken, or cracked circuit-run plating.

Resistors Burned, cracked, broken,

blistered condition.

Solder connections Cold solder or rosin joints. Resolder joint and clean with isopropyl

Repair failed module, or remove and replace with a new module.

alcohol.

VM100 & VM101 Service Manual

T able 6–3: Internal inspection check list (Cont.)

Item Repair ActionInspect For

Capacitors Damaged or leaking cases.

Corroded solder on leads or terminals.

Semiconductors Loosely inserted in sockets.

Distorted pins.

Maintenance

Repair failed module, or remove and replace with a new module.

Firmly seat loose semiconductors. Remove devices that have distorted pins. Carefully straighten pins (as required to fit the socket), and reinsert firmly. Ensure that straightening action does not crack pins, causing them to break off.

Wiring and cables Loose plugs or connectors.

Burned, broken, or frayed wiring.

Chassis Dents, deformations, or dam-

aged hardware.

Firmly seat connectors. Repair or replace modules with defective wires or cables.

Straighten, repair, or replace defective hardware.

CAUTION. To prevent damage from electrical arcing, ensure that circuit boards and components are dry before applying power to the video measurement set.

Cleaning Procedure — Interior. To clean the video measurement set interior, perform the following steps:

1. Remove the top cover (see page 6–8) to gain access to the internal parts.

2. Blow off dust with dry, low-pressure, deionized air (approximately 9 psi).

3. Remove any remaining dust with a lint free cloth dampened with a 75%

isopropyl alcohol solution.

NOTE. After you perform steps 1 through 3, if the video measurement set is clean upon inspection, skip the remaining steps.

If steps 1 through 3 do not remove all the dust or dirt, the video measurement set may be spray washed using a solution of 75% isopropyl alcohol (see steps 4 through 7).

4. Spray wash dirty parts with the isopropyl alcohol and wait 60 seconds for the

VM100 & VM101 Service Manual

majority of the alcohol to evaporate.

6–5

Maintenance

5. Use hot (48.9_ C to 60_ C/120_ F to 140_ F) deionized water to thoroughly

rinse the parts.

6. Dry all parts with low-pressure, deionized air.

7. Use low-temperature (51.7_ C to 65.6_ C/125_ F to 150_ F) circulating air

in an oven or drying compartment to dry all components and assemblies.

6–6

VM100 & VM101 Service Manual

Removal and Replacement Procedures

This section describes how to remove and replace the major mechanical and electrical modules.

H Summary of Procedures on page 6–7 lists the procedures for removal and

replacement of modules

H Tools Required on page 6–8 describes the tools needed to perform the

procedures

H Beginning with top cover on page 6–8, detailed procedures describe the

removal and replacement of modules

Preparation

Read the following warning statement and the Summary of Procedures on page 6–7 before removing a module.

WARNING. Before doing this or any other procedure in this manual, read the

General Safety Summary and Service Safety Summary found at the beginning of this manual. Also, to prevent possible injury to service personnel or damage to electrical components, read Preventing ESD on page 6–1.

Summary of Procedures

The procedures are listed below in the order in which they appear in this section:

H Top Cover on page 6–8 describes how to replace the top cover H front panel on page 6–9 describes how to replace the front panel board (A1) H main board on page 6–11 describes how to replace the main board (A2) H Power Supply on page 6–13 describes how to replace the power supply

H LCD board on page 6–14 describes how to replace the LCD board (A4) H lithium battery on page 6–16 describes how to replace the lithium battery

VM100 & VM101 Service Manual

board (A3)

(A2U100)

6–7

Removal and Replacement Procedures

Tools Required

Table 6–4 lists the tools needed to replace modules. Tools required to remove and replace each module are listed before the procedure.

T able 6–4: Tools required for module replacement

Name Description

Screwdriver with a T-10 Torx tip Standard tool Screwdriver with a #1 Pozidriv tip Standard tool 9/16 inch nut driver or wrench Standard tool 3/16 inch nut driver or wrench Standard tool Soldering iron Standard tool

Top Cover

Removal

Use the following procedure to remove the top cover.

Disconnect the power cord. Disconnect any cables from the instrument. Refer to Figure 6–1, and use the following procedure.

Place the instrument on its feet with the top cover up and remove the 11 screws that secure the top cover to the chassis, and remove the top cover.

Screws (3 on top)

Screws (4 on each side)

6–8

Figure 6–1: Top cover replacement

VM100 & VM101 Service Manual

Removal and Replacement Procedures

Replacement

Front Panel

Removal

Use the following procedure and Figure 6–1 to replace the top cover.

Place the instrument on its feet so the main board (A2) faces up. Place the top cover onto the chassis and replace the 11 screws that secure the

top cover to the chassis.

Use the following procedure to remove the front panel board (A1).

You will need a screwdriver with a T-10 Torx tip to replace the front panel board (A1).

1. Perform the top cover removal procedure (see page 6–8).

2. To unlock connector A2J9 (Figure 6–2), lift up on the blue locking tab.

Unplug the ribbon cable from A2J9.

3. Unplug the ribbon cables connected between the front panel assembly and A2J20 and A2J24 on the main board (A2).

4. Remove the two screws (bottom side of the chassis) that secure the front panel assembly to the chassis.

Figure 6–2: Front panel assembly replacement

5. Place the front panel assembly face down (Figure 6–3). Remove the 4 screws

VM100 & VM101 Service Manual

A2J24

A2J20

A2J9

Front panel assembly

Screws (2)

that secure the front panel board (A1) to the front subpanel.

6–9

Removal and Replacement Procedures

Replacement

Screws (4)

Ribbon cable to A1J1 (remove from socket)

Front panel board (A1)

Metal shield

Figure 6–3: Front panel board replacement

6. Lift the board from the front panel assembly.

7. To unlock connector A1J1, lift up on the blue locking tab. Then unplug the

ribbon cable from the front panel board (A1).

Use the following procedure and Figures 6–2 and 6–3 to replace the front panel board (A1).

1. If necessary, unlock connector A1J1. Then replace the 8-conductor ribbon

cable and lock the connector.

2. Place the front panel assembly face down (Figure 6–3).

3. Insert the edge of the front panel board (A1) between the LCD board (A4)

and its metal shield. Then align the front panel buttons so the front panel board (A1) rests evenly on the front subpanel.

4. Replace the four screws to secure the front panel board (A1) to the front

subpanel.

5. Align the front panel assembly with the instrument chassis. Replace the two

screws (bottom side of the chassis) that secure the front panel assembly to the chassis.

6. Replace the two ribbon cables from the front panel board (A1) at A2J20

(14-pin) and A2J24 (2-pin) on the main board (A2).

7. If necessary, unlock connector A2J9. Then replace the 8-conductor ribbon

cable from the front panel board (A1) and lock the connector.

8. Perform the top cover replacement procedure (see page 6–9).

6–10

VM100 & VM101 Service Manual

Main Board

Removal and Replacement Procedures

You will need a screwdriver with a size T-10 Torx tip and a size #1 Pozidriv tip, a 9/16 inch and 3/16 inch nut driver or wrench, and a soldering iron to replace the main board (A2).

Removal

Use the following procedure to remove the main board (A2).

1. Perform the Top Cover removal procedure (see page 6–8).

2. Using a soldering iron, unsolder the two wires near the rear panel that

connect to A2J34 and A2J35 (Figure 6–4).

3. Using a 3/16 inch nut driver or wrench, remove the two jack screws that secure the RS232 connector to the rear panel.

4. Using a 9/16 inch nut driver or wrench, remove the four nuts that secure the BNCs to the rear panel.

5. Unplug the ribbon cable connected between the power supply board (A3) and A2J10.

6. Remove the eight screws that secure the main board (A2) to the chassis.

Nuts (4)

Washers (4)

Jack screws (2)

Screws (8)

Figure 6–4: Main board removal

7. To unlock connector A2J9 (Figure 6–5), lift up on the blue locking tab. Then

8. Unplug the two ribbon cables connected between the front panel board (A1)

VM100 & VM101 Service Manual

J34

J35

unplug the 8-conductor ribbon cable from A2J9.

and A2J20 and A2J24.

6–11

Removal and Replacement Procedures

9. Remove the two screws (bottom side of the chassis) that secure the front

panel assembly to the chassis. Set the front panel assembly aside.

10. Slide the main board (A2) forward until the rear-panel connectors clear the

rear panel, then lift the main board (A2) from the chassis.

Front panel assembly

A2J24

A2J20

A2J9

Screws (2)

Replacement

Figure 6–5: Front panel assembly removal

Use the following procedure and Figures 6–4 and 6–5 to replace the main board (A2).

1. Align the rear-panel connectors with the rear panel, then set the main

board (A2) in place on the chassis.

2. Replace the eight screws that secure the main board (A2) to the chassis

(Figure 6–4).

3. Using a 9/16 inch nut driver or wrench, replace the four nuts that secure the

BNCs to the rear panel.

4. Using a 3/16 inch nut driver or wrench, replace the two jack screws that

secure the RS232 connector to the rear panel.

5. Using a soldering iron, solder the two wires from the ZERO CARRIER

PULSE OUTPUT as follows:

Solder the center conductor wire to J34. Solder the ground wire to J35.

6. Connect the ribbon cable connected between the power supply board (A3)

and A2J10.

6–12

VM100 & VM101 Service Manual

Power Supply

Removal and Replacement Procedures

7. Align the front panel assembly with the instrument chassis as shown in Figure 6–5. Replace the two screws (bottom side of the chassis) that secure the front panel assembly to the chassis.

8. Replace the two ribbon cables from the front panel board (A1) at A2J20 (14 pins) and A2J24 (2 pins) on the main board (A2).

9. If necessary, unlock connector A2J9. Then replace the 8-conductor ribbon cable from the front panel board (A1) and lock the connector.

10. Perform the Top Cover replacement procedure (see page 6–9).

You will need a screwdriver with a size T-10 Torx tip and a size #1 Pozidriv tip to replace the power supply board (A3).

Removal

Use the following procedure to remove the power supply board (A3).

1. Perform the Top Cover removal procedure (see page 6–8).

2. Remove the four screws (Figure 6–6) that secure the power supply

board (A3) to the chassis.

3. Unplug the two ribbon cables from A3J1 and A3J2 on the power supply board (A3).

4. Lift the top of the plastic shield to gain access to the power supply board (A3). Then lift the power supply board (A3) from the chassis.

Plastic shield

Screws (4)

A3J2

Power supply

board (A3)

Figure 6–6: Power supply board replacement

VM100 & VM101 Service Manual

A3J1

6–13

Removal and Replacement Procedures

LCD Board

Replacement

Use the following procedure and Figure 6–6 to replace the power supply board (A3).

1. Lift the top of the plastic shield (Figure 6–6) to gain access to the chassis.

Then place the power supply board (A3) onto the chassis.

2. Connect the two ribbon cable to the power supply board (A3) as shown

below:

H Connect the 2-pin ribbon cable from the input receptacle to A3J1 H Connect the 6-pin ribbon cable from the main board (A2) to A3J2

3. Replace the four screws that secure the power supply board (A3) to the

chassis.

4. Perform the Top Cover replacement procedure (see page 6–9).

You will need a screwdriver with a size T-10 Torx tip, a size #1 Pozidriv tip, and a soldering iron to replace the LCD board (A4).

Removal

Use the following procedure to remove the LCD board (A4).

1. Perform the Top Cover removal procedure (see page 6–8).

2. Perform the front panel removal procedure (see page 6–9).

3. Remove the two screws (Figure 6–7) that secure the cover shield to the front

panel assembly.

4. Remove the two screws that secure the front frame to the front panel.

Separate the front frame from the front panel.

5. Carefully push the LCD board (A4) from the front frame.

6. Using a soldering iron, unsolder the ribbon cable from the LCD board (A4).

6–14

VM100 & VM101 Service Manual

Cover shield

Removal and Replacement Procedures

Screws (4)

Ribbon cable (unsolder)

Replacement

Front frame

LCD board (A4)

Front panel

Figure 6–7: LCD board replacement

Use the following procedure and Figure 6–7 to replace the LCD board (A4).

1. Using a soldering iron, solder the ribbon cable (Figure 6–7) to the LCD board (A4).

2. Carefully replace the LCD board (A4) into the front frame.

3. Using a lint-free cloth, clean the LCD display and the clear window on the

front panel.

4. Replace the front panel over the front frame.Replace the two screws that secure the front frame to the front panel.

5. Place the cover shield over the LCD board (A4). Replace the two screws that

6. Perform the front panel replacement procedure (see page 6–10).

7. Perform the Top Cover replacement procedure (see page 6–9).

VM100 & VM101 Service Manual

secure the cover shield to the front panel assembly.

6–15

Removal and Replacement Procedures

Lithium Battery

WARNING. To avoid personal injury due to improper handling of lithium batteries, read Battery Disposal on page 6–2 before proceeding.

You will need a screwdriver with a size T-10 Torx tip and a size #1 Pozidriv tip, a 9/16 inch and 3/16 inch nut driver or wrench, and a soldering iron to replace the lithium battery.

Removal

Use the following procedure to remove the lithium battery (A2U100)

1. Perform the Top Cover removal procedure (see page 6–8).

2. Perform the main board removal procedure (see page 6–11).

3. Using a soldering iron, unsolder A2U100 from the main board (A2)

(Figure 6–8).

A2U100 (contains lithium battery)

Figure 6–8: Lithium battery replacement

6–16

Replacement

Use the following procedure and Figure 6–8 to replace the lithium battery (A2U100).

1. Using a soldering iron, solder the lithium battery (Figure 6–8) to the main

board (A2).

2. Perform the main board replacement procedure (see page 6–12).

3. Perform the Top Cover replacement procedure (see page 6–9).

VM100 & VM101 Service Manual

Troubleshooting

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.

To prevent possible injury to service personnel or damage to electrical components, read Preventing ESD on page 6–1.

This section contains information and procedures designed to help you isolate faults within the video measurement set.

Refer to the following sections for troubleshooting instructions: H Testing the Lithium Battery on page 6–18 describes how to determine when

to replace the lithium battery (A2100)

H Power Supply Limits on page 6–19 describes the power supply voltages,

limits, and test points

H Troubleshooting the main board (A2) on page 6–20 explains how to isolate

faults when the main board (A2) requires repair

NOTE. The main board (A2) contains most electrical components within the video measurement set.

If the video measurement set has power supplies that are within limits and an operational front panel and LCD display, the main board (A2) needs to be repaired or replaced.

After you locate the faulty module, refer to the following sections to complete the repairs:

H Use the Removal and Installation Procedures that begin on page 6–7 for

module replacement instructions

H Refer to Table 5–1 on page 5–1 to determine if adjustments are required after

module replacement.

H Complete the procedures found in the Performance Verification section to

verify instrument functionality following repairs or adjustment

VM100 & VM101 Service Manual

6–17

Troubleshooting

Equipment Required

The test equipment needed to troubleshoot the video measurement set depends on the type of failure. Many faults can be detected using a digital multimeter, oscilloscope, and test signal generator. However, video measurement set testing and adjustments might be required to correct some faults. Under those circumstances you will need the test equipment listed in the Performance Verification and Adjustment Procedures sections.

A computer (PC) and terminal emulator or communication program are needed to isolate faults using the ACQ:SHOW command. See page 6–28 for details.

Testing the Lithium Battery

The video measurement set contains one lithium battery (A2U100). The battery provides power to the NVRAM when AC power is disconnected. If the video measurement set has the following symptoms after you disconnect AC power, replace the battery:

H Memory does not retain saved measurement results H Memory does not retain calibration data H Memory does not retain configuration parameters

Refer to page 6–16 for replacement instructions.

6–18

VM100 & VM101 Service Manual

Power Supply Limits

Troubleshooting

This section shows the power supply test points and provides operating limits. See Figure 6–9 for a listing of the power supplies in the video measurement set.

Main board (A2)

A2J10

A2U109

Test Point Power Supply Limits

A2J10 pin 1 +12 V +1 1.76 V to +12.24 V A2U109 pin 5 +8 V +7.84 V to +8.16 V A2J10 pin 3 +5.1 V +4.85 V to +5.15 V A2L20 –5 V –4.75 V to –5.25 V A2U3 pin 5 –8 V –7.84 V to –8.16 V A2J10 pin 6 –12 V –11.4 V to –12.6 V

Figure 6–9: Power supply test points and limits

A2L20

A2U3

VM100 & VM101 Service Manual

6–19

Troubleshooting

Troubleshooting the main board (A2)

This section provides the following troubleshooting information for locating faults on the main board (A2):

H Power on diagnostics H Examples of analog signal measurements H Phase lock and DSP diagnostic LEDs and key signals H ACQ:SHOW command H Troubleshooting the VM140 or VM141 System

Power-On Diagnostics

The host processor performs a limited set of system diagnostics during the power on sequence. When power is turned on, the reset circuit (U79) ensures that the host processor powers up to a known state. The host processor then runs the program in boot ROM U61 to execute the diagnostics as shown in Table 6–5. Use the results of the power-on diagnostics to locate faults within the host processor system.

See Figure 6–10 to locate the power on diagnostics LED DS2.

T able 6–5: Power-on diagnostics

Diagnostic Test Indication of Successful Test

Initialize the memory mapped I/O and bus control logic (program the internal chip select logic and interrupts)

Checksum test for boot ROM U61 LED DS2 blinks one time (if the test

Host processor enables the external data and address buses (U62, U63, U66, U70, U73, U76, U77, U78)

Host processor testing the system SRAM U71, U72, U103, U108 (excluding acquisition and DSP memory)

The program switches to Flash EPROM memory (U101 and U102) for normal operation

LED DS2 blinks one time

fails, the LED blinks continuously) LED DS2 blinks two times

LED DS2 blinks three times

LCD Display is enabled; LED DS2 blinks five times

6–20

VM100 & VM101 Service Manual

A2DS1

Troubleshooting

A2DS3

Examples of Analog

Signal Measurements

A2DS2

Main board (A2)

Figure 6–10: Location of diagnostic LEDs

By connecting a test signal to the INPUT connector, you can use an oscilloscope to measure waveforms in the signal path up to the A/D Converter. Compare your measured waveforms to the example waveforms in this section to determine if the analog section of the main board (A2) is functioning properly.

You can also measure the output of A/D Converter A2U22 using an oscilloscope. When you apply a luminance ramp signal to the INPUT of the video measurement set, the output bits from A2U22 toggle at increasing rates. The least significant bit (pin 16) toggles at the fastest rate and the most significant bit (pin 28) toggles at the slowest rate. Trigger the oscilloscope on the /ACQUIRE signal (A2TP34 or A2U39 pin 1) for best results.

NOTE. The example waveforms are PAL format signals taken from a VM101. If your video measurement set is a VM100 (NTSC), the waveforms you measure will have a different horizontal scale.

Perform the following steps to measure the example waveforms shown in Figure 6–12 through Figure 6–16. Refer to the circuit board illustrations in the Diagrams section for test point locations.

1. Connect the test equipment as shown in Figure 6–11.

VM100 & VM101 Service Manual

6–21

Troubleshooting

TV signal generator

VM10X (rear)

Output

BNC cable

Input

75 W

Figure 6–11: Setup for measuring analog signals

2. On the video measurement set, press the CONFIG button.

3. Press the ↵ enter button to enter the CONFIG MEAS submenu.

4. Press the ↓ arrow button to scroll through the measurements. Press the

→ arrow button to select LUM NON-LIN= Off and HUM= Off.

5. Press the ↵ enter button to exit the CONFIG MEAS submenu.

6. Press the ↓ arrow button to scroll through the CONFIG menu. Press the

→ arrow button to select REF= INPUT.

7. Press the MEAS and AVG buttons (averaging should be on).

8. On the TV signal generator, set the output for a Luminance Ramp signal.

9. Use an oscilloscope to measure the waveforms.

6–22

VM100 & VM101 Service Manual

Troubleshooting

Figure 6–12: Waveform at A2TP9

Figure 6–13: Waveform at A2TP10

VM100 & VM101 Service Manual

6–23

Troubleshooting

Figure 6–14: VIDEO waveform at A2TP31

6–24

Figure 6–15: COMP_SYNC waveform at A2TP15

VM100 & VM101 Service Manual

Troubleshooting

Phase Lock and DSP

Diagnostic LEDs and Key

Signals

Figure 6–16: FIELD waveform at A2TP16

The main board (A2) contains two LEDs, DS1 and DS3, that indicate the status of the Phase Lock and DSP circuits. See Figure 6–10 on page 6–21 for the location of each LED. Under normal conditions DS1 (DSP) is on and DS3 (Phase Lock) is off.

NOTE. If the video measurement set is configured for an external reference and a suitable signal is not connected to the EXT REF input, DS3 will turn on.

DS1. Indicator DS1 lights when the video measurement set is ready to acquire a signal. A signal does not need to be connected to the INPUT connector. If DS1 fails to light, either the DSP phase lock loop is not working or the host processor has failed to program the DSP.

To isolate the fault, test the Phase Lock circuit operation as described below. If the Phase Lock circuit is operating correctly, the fault is most likely in the DSP/Data Acquisition circuits that include A2U48, A2U99, and their surrounding components.

VM100 & VM101 Service Manual

6–25

Troubleshooting

DS3. Indicator DS3 lights when the video measurement set is unable to achieve phase lock. If DS3 is illuminated, check for the following signals (refer to the circuit board illustrations in the Diagrams section for test point locations):

H DC voltage between +1 V and +4 V at measured at A2TP19 H Video signal with burst and sync components measured at A2R353 (similar

to Figure 6–12 on page 6–23)

H The COMP_SYNC signal measured at A2TP15 (see Figure 6–15) H HPULSE measured at A2TP18 (see Figure 6–18) H DSP_RCK measured at A2U48 pin 1 (see Figure 6–19) H The 8FSC_IN and /8FSC_IN signals measured at A2U116 pins 7 and 8 (see

Figure 6–17)

NOTE. The 8FSC_IN and /8FSC_IN signals are 180° out of phase, but otherwise identical. Figure 6–17 only shows an example of the 8FSC_IN waveform.

Digital control signals such as NTSC/PAL and SYNC/BURST (A2U31 pins 36 and 74, respectively) can also cause the Phase Lock circuit to fail. Check for digital control failures if DS3 is illuminated but you measure correct test waveforms.

6–26

Figure 6–17: 8FSC_IN waveform at A2U116 pin 7

VM100 & VM101 Service Manual

Troubleshooting

Figure 6–18: HPULSE waveform at A2TP18

Figure 6–19: DSP_RCK waveform at A2U48 pin 1

VM100 & VM101 Service Manual

6–27

Troubleshooting

ACQ:SHOW Command

The ACQ:SHOW command is a remote command you can send to test the functionality of the video measurement set. The command causes the host processor to transfer a coarse representation (approximately 24 × 80) of the signal from memory to the PC display (Figure 6–20).

NOTE. The ACQ:SHOW command is only intended for use by qualified service personnel when troubleshooting the video measurement set. Do not use the command for any other video measurement set applications.

If you are not able to send the ACQ:SHOW command (the RS-232 does not function properly), verify that rotary switch A2S1 is set fully clockwise (pointing to DEFAULT label on the circuit board).

 

************* ** ******** * * * ** * * * * *** * * * * *** ****** * * * *** * * * * *** * * * * *** * * * * *** ***** * * * *** * * * * **** * * * * **** * ** * * * **** * *** * * **** ***** *** * * ***** * **** * * * ***** * **** * * * ***** * * ********* ********************** * ***** * ***** * ***** * ***** * **** * * *******

6–28

Figure 6–20: Example of the ACQ:SHOW command PC display

The ACQ:SHOW command isolates failures within the host processor and DSP circuits. If the PC displays the ACQ:SHOW waveform correctly, the host processor is able to access RAM and successfully read data from and write data to the RAM; the failure is most likely in the DSP circuit.

If the PC cannot display the ACQ:SHOW waveform and you can measure the analog waveform at the A/D Converter input, the failure is most likely in the host processor or in the acquisition circuits.

VM100 & VM101 Service Manual

Troubleshooting

NOTE. Under some conditions, the host processor and memory circuits could fail and still allow the PC to display the ACQ:SHOW waveform.

To display the ACQ:SHOW waveform on a PC, perform the following steps:

1. Connect the equipment as shown in Figure 6–21.

TV signal generator

VM10X (rear)

75 W

Input

Output

BNC cable

Figure 6–21: Setup for using the ACQ:SHOW command

2. Run the terminal emulator or communication program on the PC.

NOTE. To avoid data transfer problems, do not use a file transfer protocol such as Kermit or XMODEM.

3. Configure the video measurement set RS-232 serial port for computer operation.

4. Configure the video measurement set RS-232 parameters to match the required settings for your computer.

NOTE. Refer to your computer manual to determine the settings for baud rate, stop bits, parity, and flow control.

5. On the TV signal generator, set the output for a video signal in the correct

6. Send the following command to the video measurement set:

7. Check the PC display for the ACQ:SHOW waveform (Figure 6–20).

VM100 & VM101 Service Manual

format for your video measurement set (NTSC or PAL).

ACQ:SHOW f1,8

6–29

Troubleshooting

NOTE. You can use either F1 or F2 with any valid line number as arguments for the ACQ:SHOW command. Valid line numbers are 9 – 263 for F1 and 9 – 262 for F2 for the VM100, and 6 – 310 for F1 and 318 – 623 for F2 for the VM101.

After completing the ACQ:SHOW command, the video measurement set will reacquire the signal.

Troubleshooting the

VM140 or VM141 System

The waveform monitor control function allows you to simultaneously view the waveform on a 1740A-series waveform monitor while the video measurement set measures the signal parameters. The video measurement set automatically sends line select commands to the waveform monitor to control the monitor display. The resulting waveform display is the video line where the video measurement set is performing measurements.

The video measurement set and waveform monitor system is called a VM140 when the video measurement set is a VM100. The system is a VM141 when the video measurement set is a VM101.

If the video measurement set is unable to control the waveform monitor, use the following procedure to test the RS-232 serial port on the video measurement set:

NOTE. Use a standard 9-pin cable to connect the PC and video measurement set RS-232 serial ports. The RS-232 serial port cable used with the video measurement set and waveform monitor is not PC-compatible.

1. Connect a standard 9-pin cable between the RS-232 serial ports on the video

measurement set and a PC.

2. Run the terminal emulator or communication program on the PC.

6–30

NOTE. To avoid data transfer problems, do not use a file transfer protocol such as Kermit or XMODEM.

3. Configure the video measurement set RS-232 serial port for CONTROL

mode.

4. Configure the PC RS-232 parameters to match the CONTROL mode settings

shown in Table 6–6.

VM100 & VM101 Service Manual

Troubleshooting

T able 6–6: CONTROL mode communications parameters

Parameter PC Setting

BAUD RATE 9600 DA TA BITS 8 STOP BITS 1 PARITY NONE FLOW CTL NONE

5. On the video measurement set, press the MEAS button. If the RS-232 serial port is functioning properly, lines of text appear on the PC screen as shown in the following example:

:sweep:timing:onel;:lines:field f2;:lines:number:ntsc 17 (signal connected) :sweep:timing twof (no signal connected)

VM100 & VM101 Service Manual

6–31

Troubleshooting

6–32

VM100 & VM101 Service Manual

Repackaging Instructions

This section contains the information needed to repackage the video measurement set for shipment or storage.

Packaging

Use a corrugated cardboard shipping carton having a test strength of at least 275 pounds (125 kg) and with an inside dimension at least six inches (15.25 cm) greater than the instrument dimensions.

If the instrument is being shipped to a Tektronix Service Center, enclose the following information:

H The owner’s address H Name and phone number of a contact person H Type and serial number of the instrument H Reason for returning

Storage

H A complete description of the service required Seal the shipping carton with an industrial stapler or strapping tape. Mark the address of the Tektronix Service Center and also your own return

address on the shipping carton in two prominent locations.

Store the video measurement set in a clean, dry environment. The following environmental characteristics apply for both shipping and storage:

H Temperature range: –40° F to +167° F (–40° C to +75° C) H Altitude: To 50,000 feet (15,240 meters)

See Table 1–6 on page 1–5 for a complete listing of the environmental charactertistics.

VM100 & VM101 Service Manual

6–33

Repackaging Instructions

6–34

VM100 & VM101 Service Manual

Tektronix VM101, VM100 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of Contents

Specifications

Operating Information

Theory of Operation

Performance Verification

Adjustment Procedures

Maintenance

Options

Replaceable Electrical Parts

Diagrams

Replaceable Mechanical Parts

List of Figures

List of Tables

General Safety Summary

Service Safety Summary

Preface

Related Manuals

Service Manual Conventions

Strategy for Servicing

Adjustment Interval

Tektronix Service Offerings

Contacting Tektronix

Specifications

Product Description

Specification Tables

Electrical Specifications

Environmental Characteristics

Safety Standards and Certification

Physical Characteristics

Remote Control Port

Operating Information

Installation

Operating Information

Theory of Operation

Logic Conventions

Block Level Description

Detailed Circuit Description

Performance Verification

General Information

Prerequisites

Equipment Requirements

Test Record

Performance V erification Procedure

Adjustment Procedures

General Information

Requirements

Adjustment Procedure

Maintenance

Preventing ESD

Battery Disposal

Inspection and Cleaning

Removal and Replacement Procedures

Preparation

Summary of Procedures

Tools Required

Top Cover

Front Panel

Main Board

Power Supply

LCD Board

Lithium Battery

Troubleshooting

Equipment Required

Testing the Lithium Battery

Power Supply Limits

Troubleshooting the main board (A2)

Repackaging Instructions

Packaging

Storage