Tektronix 071-1143-01 - Manuals

Table of Contents WFM90D and WFM91D Service Manual iii Connector Diagram 6-- 59 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Options Options 7-- 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

Table of Contents iv WFM90D and WFM91D Service Manual List of Figures Figure 2--1: Installing the viewing hood 2--2 . . . . . . . . . . . . . . . . . . . . . . . Figure 2--2: Installing the desk stand 2--2 . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2--3: Packing the Option 33 travel ...

Table of Contents vi WFM90D and WFM91D Service Manual List of Tables Table 1--1: Vertical deflection system 1--2 . . . . . . . . . . . . . . . . . . . . . . . . . Table 1--2: DC restoration 1--4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1--3: Audio mode 1--5 . . . ....

WFM90D and WFM91D Service Manual vii General Safety Summary Review the following safety precautions to avoid injury and prevent damage tothis product or any products connected to it. To avoid potential hazards, use this product only as specified. Only qualified personnel should perform service proce...

General Safety Summary viii WFM90D and WFM91D Service Manual Terms in this Manual. These terms may appear in this manual: WARNING. Warning statements identify conditions or practices that could result in injury or loss of life. CAUTION. Caution statements identify conditions or practices that could ...

WFM90D and WFM91D Service Manual ix Service Safety Summary Only qualified personnel should perform service procedures. Read this Service Safety Summary and the General Safety Summary before performing any service procedures. Do Not Service Alone. Do not perform internal service or adjustments of thi...

WFM90D and WFM91D Service Manual xi Preface This manual provides instructions for servicing the WFM90D and WFM91DHandheld Waveform, Vector, Picture, and Audio Monitors. This manualdescribes features and specifications that are common to all generator modules.These include system configuration and th...

Preface xii WFM90D and WFM91D Service Manual Contacting Tektronix Phone 1-800-833-9200 * Address Tektronix, Inc.Department or name (if known)14200 SW Karl Braun DriveP.O. Box 500Beaverton, OR 97077USA Web site www.tektronix.com Sales support 1-800-833-9200, select option 1 * Service support 1-800-83...

WFM90D and WFM91D Service Manual 1- 1 Specifications This section includes the following information: H Product description H Specifications tables Product Description The handheld, self-contained, Tektronix WFM90D and WFM91D television waveform monitors can monitor analog and digital signals. The m...

Specifications 1- 2 WFM90D and WFM91D Service Manual Characteristics Tables The tables use the following abbreviations: Performance Requirement (Req). All performance requirements in the specifica- tion tables are identified with Req , and can be assured by completing the Performance Check Procedure...

Specifications 1- 8 WFM90D and WFM91D Service Manual Physical Characteristics Table 1- 8: Physical characteristics Category Description Dimensions REF: Instrument: 5 inches (127 mm).3.15 inches (80.0 mm).9.6 inches (243.8 mm). Shipping Box: 13.25 x 13.75 x 6 inside14 x 14.25 x 6.25 outside Weight RE...

Specifications WFM90D and WFM91D Service Manual 1- 9 Certification and Compliances Table 1- 10: Certifications and Compliances Category Standards or description EC Declaration of Conformity -- EMC Meets the intent of Directive 89/336/EEC for Electromagnetic Compatibility. Compliances were demonstrat...

WFM90D and WFM91D Service Manual 2- 1 Installation This section contains the following information: H Mechanical installation instructions H Electrical installation instructions H Operating instructions that relate to the service of this instrument Mechanical Installation Before installing the WFM90...

Installation 2- 2 WFM90D and WFM91D Service Manual Figure 2- 1: Installing the viewing hood The desk stand holds the monitor upright on a flat surface. Insert the prongs ofthe stand into the holes in the back of the instrument as shown in Figure 2--2. Figure 2- 2: Installing the desk stand Desk Stan...

Installation WFM90D and WFM91D Service Manual 2- 3 The travel case (Option 33) can safely hold the handheld monitor and itsaccessories while traveling between locations. The case also holds a companionhandheld TSG95 or TSG601 generator. The travel case compartments (seeFigure 2--3) hold the followin...

Installation 2- 4 WFM90D and WFM91D Service Manual Electrical Installation Follow these instructions for electrical installation. There are no internal jumper settings for these monitors. Instrument configura-tion is through the CONFIG menu (refer to page 2--21). The WFM90D and WFM91D handheld monit...

Installation WFM90D and WFM91D Service Manual 2- 5 NOTE . To prevent a loss of battery power, be sure that the battery connector tab snaps on to the jumper housing. Press Grasp wire Figure 2- 4: Removing the NiMH battery pack You can use six alkaline batteries to power the WFM90D and WFM91D , howeve...

WFM90D and WFM91D Service Manual 2- 7 Functional Overview This section describes the WFM90D and WFM91D controls and connectors. Keypad Controls The keypad (front panel) is illustrated in Figure 2--6. ON. The ON button toggles the instrument power on and off. The current instrument keypad and menu se...

Functional Overview WFM90D and WFM91D Service Manual 2- 9 The menus use a combination of onscreen readout and multi-use buttons, inconjunction with the Arrow Buttons, to control most of the monitoring functions.Menus are entered by pressing one of the MENU, CONFIG, or LINE SELbuttons. Menus are exit...

Functional Overview 2- 10 WFM90D and WFM91D Service Manual Extraordinary conditions may cause the WFM90D and WFM91D controls to become locked or to respond erratically. To reset the instrument, first press theON button to turn off the power, then press the ON button again while holdingdown the WIP a...

Functional Overview 2- 12 WFM90D and WFM91D Service Manual Onscreen Readouts The WFM90D and WFM91D use onscreen messages to alert you to certain monitoring conditions. Figure 2--8 shows example readout messages and theirlocations. 20 40 60 80 100 -- 20 -- 40 0 GAIN UNCAL 10uS/DIV EXT REF VX.XX LOW B...

WFM90D and WFM91D Service Manual 2- 15 Using the Menus This section describes the operating and configuration menus for the WFM90D and WFM91D . Figure 2--9 and Figure 2--10 show the complete menu structure for all of theoperating menus. Figure 2--12 (on page 2--22) shows the menu structure for theCo...

Using the Menus WFM90D and WFM91D Service Manual 2- 17 Operating Menus The following pages describe the operating menus, shown in Figure 2--9 andFigure 2--10. Each operating mode has an associated menu. In addition, the Waveform, Vector,Picture, and WIP operating modes have an associated digital men...

Using the Menus 2- 18 WFM90D and WFM91D Service Manual Table 2- 2: Waveform menu choices, analog and digital Submenu Digital only Function GAIN Sets the Waveform display mode vertical gain and theVector display mode gain to X1 or X5. FILTER Selects FLAT (unfiltered display) or LUM (low-passfiltered ...

Using the Menus WFM90D and WFM91D Service Manual 2- 19 Press the AUDIO button and the MENU button to open the Audio operatingmenu. There is no digital menu for audio. For more details on menu access, seepage 2--17. Audio menu choices are shown in Table 2--3. The Audio menu tree is shown inFigure 2--...

Using the Menus 2- 20 WFM90D and WFM91D Service Manual Press the WIP button and the MENU button to open the Waveform-in-Pictureoperating menu. Hold the MENU button in for two seconds to open the digitalmenu. For more details on menu access, see page 2--17. WIP menu choices are shown in Table 2--5. T...

Using the Menus 2- 26 WFM90D and WFM91D Service Manual Line Select Menu Enter the Waveform, Vector, or WIP operating mode. Press the LINE SEL button to turn on Line Select mode and open the Line Selectmenu. The number of the selected line and/or field displays in the menu bar overthe right two Bezel...

WFM90D and WFM91D Service Manual 3- 1 Theory of Operation This section contains a module-level description of the instrument circuitry. Thedescription is based on the block diagram in Figure 3--1. (For serial numbersbelow B020100, see Figure 3--2). Input Board The signal input and output connectors ...

Theory of Operation 3- 2 WFM90D and WFM91D Service Manual Top Board The Top board contains the microprocessor circuitry, the rasterizer and graphicsgenerator, the subcarrier oscillator, and the timing generator. Microprocessor. The microprocessor takes input from the front-panel keypad to control th...

WFM90D and WFM91D Service Manual 4- 1 Performance Verification This section contains the following information: H Summary verification procedure H List of equipment required to perform the procedures H Performance Verification Procedures: Analog Section H Performance Verification Procedures: Digital...

Performance Verification 4- 2 WFM90D and WFM91D Service Manual The tests in this section comprise a valid confirmation of instrument performancewhen the following requirements are met: H Test equipment used to verify performance requirements must be calibratedand working within the limits specified ...

Performance Verification WFM90D and WFM91D Service Manual 4- 3 Table 4- 1: Summary verification procedure (Cont.) Procedure Page # Procedure requirement Vector phase stability Phase Shift with Subcarrier Frequency Change from F SC to F SC 50 Hz (F SC 10 Hz PAL): 2 ° . Phase Shift with Burst Amplitud...

WFM90D and WFM91D Service Manual 4- 5 Performance Verification: Analog Section Perform the following steps before beginning the verification procedures: 1. Plug the AC power adapter into the instrument and then plug the adapter intothe AC power source. 2. Connect the multiburst signal from the analo...

Performance Verification: Analog Section 4- 6 WFM90D and WFM91D Service Manual Sweep Timing and Integral Linearity This procedure verifies the following requirement: Sweep Timing Accuracy: 5 s/Div. (1 Line), 10 s/Div. (2 Line), and 1.0 s/Div. (2 Line + MAG), 2%. 0.2 s/Div. (1 Line + MAG) 3%. Integra...

Performance Verification: Analog Section 4- 8 WFM90D and WFM91D Service Manual 2. Select VAR GAIN ON from the Configuration menu. 3. Check by adjusting the Variable Gain controls that the signal amplitude can be displayed less than 70 IRE (500 mV PAL). 4. Set the VAC for a 799.9 mV output. 5. Check ...

Performance Verification: Analog Section WFM90D and WFM91D Service Manual 4- 9 Input and DC Restorer Frequency Response This procedure verifies the following requirement: X1 Gain Response (Flat filter selected): 50 kHz to 6 MHz within 2% of responseat 50 kHz. X5 Gain Response (Flat filter selected):...

Performance Verification: Analog Section WFM90D and WFM91D Service Manual 4- 11 Vector Phase Stability This procedure verifies the following requirement: Phase Shift with Subcarrier Frequency Change from F SC to F SC 50 Hz (F SC 10 Hz PAL): 2 ° . Phase Shift with Burst Amplitude Change from Nominal ...

Performance Verification: Analog Section 4- 12 WFM90D and WFM91D Service Manual Chrominance Bandwidth This procedure verifies the following requirement: Chrominance Bandwidth: Upper --3 dB Point: F SC + 500 kHz, 100 kHz. Lower --3 dB Point: F SC -- 500 kHz, 100 kHz. 1. Connect the precision 50 Ω cab...

Performance Verification: Analog Section WFM90D and WFM91D Service Manual 4- 13 8. Increase the frequency on the leveled sine wave generator until the edge ofthe circle display expands out to the compass rose and again reduces to the --3 dB (70%) point gaps on the vertical graticule axis. See Figure...

WFM90D and WFM91D Service Manual 4- 15 Performance Verification: Digital Section Perform the following steps before beginning the verification procedures: 1. Plug the AC power adapter into the WFM90D or WFM91D monitor andthen plug the adapter into the AC power source. 2. Connect the 75% color bar si...

Performance Verification: Digital Section 4- 16 WFM90D and WFM91D Service Manual 6. Check that the displayed video is 714 mV, 2% (approximately 1/4 major division) from graticule baseline to white bar (0 IRE to +100 IRE for 525 or0 V to +700 mV for 625). 7. Set the COMP SEL to BLUE . 8. Check that t...

Performance Verification: Digital Section WFM90D and WFM91D Service Manual 4- 17 Check Frequency Response at X5 Gain This procedure verifies the following requirement: Flat Filter, X5 Gain, 50 kHz to 4.5 MHz, within 5%. 1. Select the WFM mode on the WFM90D or WFM91D monitor. 2. Press MENU to display...

WFM90D and WFM91D Service Manual 5- 1 Adjustments This section contains the following information: H Summary adjustment procedure H List of equipment required to perform the procedures H Adjustment procedures Summary Adjustment Table 5--1 is a cross-reference to the adjustment procedure steps. Table...

WFM90D and WFM91D Service Manual 5- 5 Adjustment Procedures: Analog Section Perform these steps to prepare the instrument to be adjusted: 1. Plug the AC power adapter into the WFM90D or WFM91D, and then plugthe adapter into the AC power source. 2. Set the input termination switches to the HIZ positi...

Adjustment Procedures: Analog Section 5- 10 WFM90D and WFM91D Service Manual Yellow Cyan Blue Blue Figure 5- 1: NTSC graticule showing the vector gain adjustment 7. Select PHASE and use the arrow buttons to position the burst vector exactly on the 180 _ graticule line. 8. Select X5 GAIN , and then s...

WFM90D and WFM91D Service Manual 5- 11 Adjustment Procedures: Digital Section Perform the following steps to prepare the instrument to be adjusted: 1. Plug the AC power adapter into the WFM90D or WFM91D, and then plugthe adapter into the AC power source. 2. Set the input termination switches to the ...

Adjustment Procedures: Digital Section WFM90D and WFM91D Service Manual 5- 13 Cable Margin Perform the following steps to adjust the cable margin indicator (you areadjusting the value at which the cable flag comes on to 200 meters): 1. Connect the output from the digital signal generator to the WFM9...

WFM90D and WFM91D Service Manual 6- 1 Maintenance The maintenance or service of this instrument must be performed only byqualified service personnel who have read the Service Safety Summary and the Operating Information sections of this manual. CAUTION. If the instrument does not function properly, ...

Maintenance 6- 2 WFM90D and WFM91D Service Manual Instrument performance should be checked after each 2000 hours of operation orevery 12 months. This will help to ensure maximum performance and assist inlocating defects that may not be apparent during regular operation. PerformanceVerification and A...

WFM90D and WFM91D Service Manual 6- 3 Remove and Replace This section tells you how to remove and replace the customer replaceablemodules and parts of the WFM90D or WFM91D Handheld Waveform, Vector,Picture, and Audio Monitor. CAUTION. To prevent damage to the instrument, disconnect the power adapter...

Remove and Replace 6- 4 WFM90D and WFM91D Service Manual Procedures Table 6--2 lists the remove and replace procedures in this section and theirstarting page numbers. Table 6- 2: Remove and replace procedure list Replaceable part Page number Top cover 6 --5 LCD display lens 6 --5 LCD Display Assembl...

Remove and Replace WFM90D and WFM91D Service Manual 6- 5 Top Cover Assembly The top cover assembly contains replaceable subparts. Procedures for removingthe subparts are included below. Remove. To remove the top cover assembly: 1. Remove the six retaining screws using the Torx-tip screwdriver. SeeFi...

Remove and Replace WFM90D and WFM91D Service Manual 6- 7 LCD Display Assembly The LCD display assembly does not contain any replaceable subparts. If youneed to replace any part of the display assembly, you must replace the entireassembly. CAUTION. To avoid damaging the LCD display, do not touch the ...

Remove and Replace 6- 8 WFM90D and WFM91D Service Manual For instruments with serial numbers B020100 and above. Remove. To remove the LCD Display assembly: 1. Remove the top cover. Refer to Top Cover on page 6--5. 2. Grasp the sides of the Display assembly and lift the assembly as shown inFigure 6--...

Remove and Replace WFM90D and WFM91D Service Manual 6- 11 Instructions for serial numbers below B020100. This procedure tells how toremove and replace an LCD Display assembly (for example, to gain access toanother module). However, if you need to replace the LCD Display assemblywith a new one, pleas...

Remove and Replace 6- 14 WFM90D and WFM91D Service Manual To replace a faulty backlight for instruments with serial numbers B020100 andabove, you must install a new LCD display assembly. However, the backlight is separately replaceable in instruments with serialnumbers below B020100. Remove. To remo...

Remove and Replace WFM90D and WFM91D Service Manual 6- 15 Top Board Assembly The Top board assembly contains replaceable subparts. Remove. To remove the Top board: 1. Remove the top cover. Refer to Top Cover on page 6--5. 2. Remove the two retaining screws from the top of the Top board. 3. Gently pu...

Remove and Replace 6- 16 WFM90D and WFM91D Service Manual Remove. To remove the keypad: 1. Remove the top cover. Refer to Top Cover on page 6--5. 2. Remove the Top board. Refer to Top Board on page 6--15. 3. Gently pull the keypad from the Top board. Replace. To replace the keypad: 1. Press the nubs...

Remove and Replace WFM90D and WFM91D Service Manual 6- 17 Remove. To remove the Top board shield: 1. Remove the top cover. Refer to Top Cover on page 6--5. 2. Remove the two retaining screws from the top of the Top board. 3. Slide the Top board shield out from under the Top board. Replace. To replac...

Remove and Replace WFM90D and WFM91D Service Manual 6- 21 To remove the SDI Interface board: 1. Remove the top cover. Refer to Top Cover on page 6--5. 2. Remove the battery cover. Refer to Battery Cover on page 6--25. 3. Lift on the Bottom board while pressing on the battery connector in thebattery ...

Remove and Replace 6- 22 WFM90D and WFM91D Service Manual The following procedure tells you how to remove the Backlight board andreinstall the same board (for example, to gain access to another assembly). Toreplace the Backlight board, you must replace the LCD Display assembly;contact your Tektronix...

Remove and Replace 6- 24 WFM90D and WFM91D Service Manual Remove. To remove the Input board: 1. Remove the top cover. Refer to Top Cover on page 6--5. 2. Remove the battery cover. Refer to Battery Cover on page 6--25. 3. Lift on the Bottom board while you press on the battery connector in thebattery...

Remove and Replace WFM90D and WFM91D Service Manual 6- 25 Battery Cover Assembly The battery cover assembly contains replaceable subparts. Procedures forremoving the subparts are included. Remove. To remove the battery cover assembly: 1. Turn the turnlock stud 1/4-turn counterclockwise. 2. Pull outw...

Remove and Replace 6- 26 WFM90D and WFM91D Service Manual Battery cover Figure 6- 11: Installing the battery cover Remove. To remove the turnlock stud and bushing: 1. Remove the battery cover. Refer to Battery Cover on page 6--25. 2. Gently pry up on the outside portion of the bushing as shown inFig...

Remove and Replace 6- 28 WFM90D and WFM91D Service Manual Remove. To remove the battery cushion pad: 1. Remove the battery cover. Refer to Battery Cover on page 6--25. 2. To remove the cushion pad, pry it up around the edges and pull it off of thebattery cover. 3. If necessary, clean the surface of ...

Remove and Replace WFM90D and WFM91D Service Manual 6- 29 Press Grasp wire Figure 6- 13: Removing the NiMH battery pack Remove. To remove the C-size alkaline batteries: 1. Remove the battery cover. Refer to Battery Cover on page 6--25. 2. Carefully pull the batteries out of the battery compartment. ...

Remove and Replace WFM90D and WFM91D Service Manual 6- 31 Bottom Cover Assembly The bottom cover assembly contains replaceable subparts. Procedures forremoving and installing the subparts are included below. Remove. To remove the bottom cover: 1. Remove any installed batteries. Refer to Batteries on...

Remove and Replace 6- 32 WFM90D and WFM91D Service Manual Replace. To replace the battery power connector: 1. Solder the battery power connector wires to the battery contacts. SeeFigure 6--16. 2. Install the bottom cover. Refer to Bottom Cover on page 6--31. Remove. To remove the battery contacts: 1...

Remove and Replace 6- 34 WFM90D and WFM91D Service Manual Remove. To remove the turnlock stud receptacle: 1. Remove the bottom cover. Refer to Bottom Cover on page 6--31. 2. Depress the retaining fingers on the turnlock stud receptacle and push thereceptacle through the bottom cover. See Figure 6--1...

Remove and Replace WFM90D and WFM91D Service Manual 6- 37 Remove. To remove the AC adapter EMI suppressor: 1. Release the retaining latches on the side of the EMI suppressor. 2. Pull the AC adapter cord from the EMI suppressor. Replace. To replace the AC adapter EMI suppressor: 1. Place the EMI supp...

WFM90D and WFM91D Service Manual 6- 39 Troubleshooting Procedures This section contains the following information to help you locate problemswithin the WFM90D or WFM91D: H List of equipment required to perform the procedures H Battery-fault analysis H Low-voltage power supply H Fault symptom table H...

Troubleshooting Procedures 6- 40 WFM90D and WFM91D Service Manual Battery-Fault Analysis NOTE . If the instrument functions properly when powered by the AC adapter, but there are battery or battery charging problems, use the following procedure. Ifthere are no battery problems or if the instrument d...

Troubleshooting Procedures 6- 42 WFM90D and WFM91D Service Manual Low-Voltage Power Supply Use the following procedure to check that the low-voltage power supplies areoperating properly before proceeding to Fault Symptom Table . 1. Disconnect the AC adapter from the WFM90D or WFM91D. 2. Remove any i...

Troubleshooting Procedures WFM90D and WFM91D Service Manual 6- 43 Fault Symptom Table NOTE . Check the low-voltage power supplies (see Low-Voltage Power Supply on page 6--42) before proceeding with the following procedure: 1. Disconnect the AC adapter from the instrument. 2. Remove any installed bat...

Troubleshooting Procedures 6- 44 WFM90D and WFM91D Service Manual Table 6- 5: Fault symptom table (Cont.) Symptom Flowchart Dim or blotchy display page 6 --58 All display modes are bad except Picture, when no menus are displayed page 6 --58 Troubleshooting Flowcharts The troubleshooting flowcharts h...

Options 7- 2 WFM90D and WFM91D Service Manual Accessories Standard accessories are shipped with every instrument. The standard accessoriesfor the WFM90D and WFM91D and the Tektronix part numbers to use when ordering are listed in Table 7--2. Table 7- 2: Standard accessories Description Quantity Tekt...

WFM90D and WFM91D Service Manual 8- 1 Replaceable Parts List This section lists the replaceable modules for this instrument. Use this list toidentify and order replacement parts. Parts Ordering Information Replacement parts are available through your local Tektronix, Inc., Field Officeor representat...

Replaceable Parts List 8- 2 WFM90D and WFM91D Service Manual Using the Replaceable Parts List This section contains a list of the mechanical and/or electrical components thatare replaceable for the WFM90D and WFM91D . Use this list to identify and order replacement parts. The following table describ...