Related Manuals for DEC VR297
Summary of Contents for DEC VR297
- Page 1 VR297 Color Monitor Service Guide Order Number EK-VR297-SV-001 digital equipment corporation maynard, massachusetts...
- Page 2 First Edition, September 1989 The information in this document is subject to change without notice and should not be construed as a commitment by Digital Equipment Corporation. Digital Equipment Corporation assumes no responsibility for any errors that may appear in this document.
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Page 3: Table Of Contents
Contents About This Guide Troubleshooting Before You Start ........Troubleshooting the Problem . - Page 4 3.12 H/J Control Block Assembly ......VR297 Documentation Alignment Screens Circle-Crosshatch Pattern ......
- Page 5 Tools and Equipment ......viii VR297 Recommended Spares List ....viii...
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Page 6: About This Guide
About This Guide This guide describes how to service your VR297 color monitor in the field. The guide covers the following topics: Troubleshooting the field replaceable units (FRUs) Adjusting the video monitor Removing and replacing FRUs Appendixes provide the following information:... - Page 7 29-25448 104 to 126 Vac, 60 Hz 29-25449 198 to 242 Vac, 50 Hz 29-25450 Recommended Spares List The following is the recommended spares list for the VR297 color monitor: Table 2 VR297 Recommended Spares List Part Number Spares Digital...
- Page 8 About This Guide Table 2 (Cont.) VR297 Recommended Spares List Part Number Spares Digital Sony L board (convergence) 29-27803 A-1235-011-A H STAT control 29-27805 1-237-344-11 Other Parts Bezel (plastic) 29-27809 X-4381-964-1 Cable assembly 29-27808 A-1499-505-A Cable clamps 29-27817 A-1499-499-A Carton 99-08577 –...
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Page 9: Troubleshooting
1.1 Before You Start This section covers the basic steps in troubleshooting any VR297 monitor problem. These steps will help you do your job in the field more easily and effectively. Section 1.2 provides the actual flowcharts for troubleshooting specific problems. - Page 10 Troubleshooting NOTE Magnetic fields affect the monitor’s performance and can give a false indication of a monitor failure. Place the monitor away from: • Electromagnetic devices, such as other monitors • Magnetized objects, such as filing cabinets and steel beams in walls Learn About the Problem Talk to the operator to get a history of the problem.
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Page 11: Troubleshooting The Problem
Troubleshooting 1.2 Troubleshooting the Problem This section provides flowcharts for troubleshooting different types of monitor problems. The flowcharts make two assumptions: • If FRUs were replaced, the correct procedures in Chapter 3 were followed. • Adjustment procedures were performed as necessary. Problems may come from two sources—your host system or your monitor. -
Page 12: No Display (1 Of 4)
Troubleshooting 1.2.1 No Display (1 of 4) START DISPLAY THE CIRCLE CROSSHATCH SCREEN THE POWER LED ON THE MONITOR ARE THE CRT FILAMENTS SET THE S1 SWITCH ON THE A BOARD TO THE AGING POSITION RASTER WHAT ONLY TYPE OF DISPLAY VIDEO IS DISPLAYED ON THE... - Page 13 Troubleshooting No Display (2 of 4) TURN OFF POWER, RESEAT THE C BOARD AND CABLES, AND TURN POWER BACK ON ARE THE CRT FILAMENTS CHECK THE VOLTAGE BETWEEN PINS H AND H ON THE C BOARD IS THE REPLACE THE VOLTAGE WHOLE MONITOR 6.5 Vdc...
- Page 14 Troubleshooting No Display (3 of 4) 1. TURN OFF POWER 2. UNPLUG THE AC POWER CORD 3. CHECK THE FUSE ON THE BACK OF THE MONITOR IS THE FUSE BLOWN CHECK THE AC POWER AT THE WALL OUTLET 1. REPLACE THE FUSE THERE POWER 2.
- Page 15 Troubleshooting No Display (4 of 4) CHECK THE VOLTAGE AT TP9 ON THE A BOARD THE VOLTAGE GREATER THAN CHECK THE C14 POINT ON THE B BOARD 55 Vdc THE VOLTAGE REPLACE THE GREATER THAN POWER SUPPLY PERFORM THE 55 Vdc (3.4) A BOARD ADJUSTMENTS (2.3)
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Page 16: Incorrect Color
Troubleshooting 1.2.2 Incorrect Color START DISPLAY THE CIRCLE CROSSHATCH SCREEN SCREEN MUST MISSING BE WHITE. IS THE A COLOR VERIFY THAT THE PROBLEM IS NOT EXTERNAL IMAGE MISSING ANY COLOR 1. CHECK THE VIDEO CABLE FOR A GOOD CONNECTION OR IS IT SATURATED 2. -
Page 17: Purity
Troubleshooting 1.2.3 Purity START DISPLAY THE GREEN SCREEN THE SCREEN DEGAUSS THE MONITOR BY COMPLETELY ONE TURNING THE POWER COLOR SWITCH OFF THEN BACK ON THE SCREEN COMPLETELY ONE COLOR STOP REPLACE THE WHOLE MONITOR... -
Page 18: Misconvergence
Troubleshooting 1.2.4 Misconvergence START DISPLAY THE CIRCLE ADJUST V CENT TO ADJUST H STAT AND V STAT CROSSHATCH SCREEN CENTER THE IMAGE TO CORRECT MISCONVERGENCE (2.4.2) (2.4.6) HORIZONTAL READJUST THE H STAT THE CONTROLS TYPE OF ONLY CONTROL NEAR THE CORRECT THE MISCONVERGENCE A BOARD (2.4.6) -
Page 19: Geometric Distortion
Troubleshooting 1.2.5 Geometric Distortion START DISPLAY THE CIRCLE CROSSHATCH SCREEN MEASURE THE DISTANCE BETWEEN THE TOP AND BOTTOM OF THE IMAGE AT SEVERAL POINTS ACROSS THE SCREEN IS THE DISTANCE FROM TOP TO BOTTOM AT PERFORM THE D BOARD EACH POINT ADJUSTMENTS (2.4) 236 mm ARE THE... -
Page 20: Excess Luminance
Troubleshooting 1.2.6 Excess Luminance START ADJUST THE CONTRAST CONTROL TO DETERMINE IF THE DISPLAY THE CIRCLE CIRCLE CROSSHATCH IMAGE CROSSHATCH SCREEN VARIES IN BRIGHTNESS DOES THE CONTRAST CHECK THE +12, 12, CONTROL INCREASE AND AND +60 VOLT POINTS DESCREASE THE ON THE B BOARD IMAGE DISCONNECT THE THREE VIDEO... -
Page 21: Bright Area At Left Margin
Troubleshooting 1.2.7 Bright Area at Left Margin START DISPLAY THE CIRCLE CROSSHATCH SCREEN ADJUST THE H PHASE CONTROL ON THE D BOARD (2.4) THE BRIGHT AREA STILL ON STOP THE SCREEN REPLACE THE A BOARD (3.7) PERFORM THE A BOARD ADJUSTMENTS (2.3) THE BRIGHT AREA STILL ON... -
Page 22: Adjustments
Adjustments This chapter shows you how to align the monitor. You do not have to perform every adjustment procedure each time you align the monitor. However, you should check all adjustments in the order shown, because many adjustments affect each other. If a setting is already correct, you can skip that adjustment and go on to the next one. -
Page 23: Before You Start
Adjustments 2.1 Before You Start Let the monitor warm up for at least 20 minutes before performing any adjustments on the monitor. The warm-up time ensures that the electron guns are at a stable temperature before you do any adjustments. NOTE If a customer calls with a display-quality problem, ask the customer to leave the monitor on until you arrive. -
Page 24: Using The Radiance Meter
Adjustments 2.2 Using the Radiance Meter You use the radiance meter when making color adjustments (Section 2.3). To use the radiance meter: 1. Remove the cap from the radiance meter’s sensor head and connect the occluder to the radiance meter. CAUTION Avoid excessive force when tightening the occluder, or you may damage the radiance meter. - Page 25 Adjustments 2. Connect the ac line adapter to the radiance meter and plug it in to a wall outlet. NOTE Make sure that your radiance meter is in calibration. 3. Turn on the power switch (down position). NOTE Do not use the POWER ON W/BACKLIGHT position when you are using the radiance meter with batteries.
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Page 26: Color Adjustments
Adjustments 2.3 Color Adjustments NOTE Make color adjustments after replacing the video amplifier board (A board). The following figure shows the location of the controls used to make the color adjustments: A Board adjustments ma-0951-89 To adjust the monitor’s color: 1. - Page 27 Adjustments 3. Turn the screen control (G2) clockwise until the screen background is visible. G2 is the bottom control on the high-voltage block. Then turn G2 counterclockwise until the screen background disappears. (Raster cut-off is not set.) 4. Turn the green background control (RV404) clockwise until the screen background is visible.
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Page 28: Deflection Adjustments
Adjustments 2.4 Deflection Adjustments NOTE You must perform the deflection adjustments if the deflection board (D board) is replaced. This section covers the following adjustments: Vertical linearity Horizontal centering Vertical centering Horizontal width Vertical height Side pincushioning Horizontal linearity Trapezoid Horizontal phase Focus For these adjustments, select the circle-crosshatch screen pattern from... -
Page 29: Vertical Linearity (V-Lin)
Adjustments 2.4.1 Vertical Linearity (V-LIN) To check and adjust vertical linearity: 1. Display the circle-crosshatch screen. 2. Check the pattern to make sure the squares are all the same height. If the squares are not all the same height, go to the next step. 3. -
Page 30: Vertical Centering, Horizontal Centering, And Screen Size
Adjustments V LIN figure 2 ma-0949-89 NOTE The V-LIN BAL control has no effect when the V-LIN control is turned completely counterclockwise (small squares in the center of the pattern). 2.4.2 Vertical Centering, Horizontal Centering, and Screen Size NOTE Make the following adjustments after completing the adjustments in Sections 2.4.1 and 2.4.3. - Page 31 Adjustments 6. Set the switch S1 on the A board to the test position (up) to produce raster. NOTE The right edge of the screen may be a purple color. To measure the size of the raster, measure to the edge of this purple section.
- Page 32 Adjustments Vertical and Horizontal Centering Standard ma-0947-89 Vertical and Horizontal Size Standard ma-0945-89...
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Page 33: Horizontal Pincushion Distortion
Adjustments 2.4.3 Horizontal Pincushion Distortion When the sides of a video display are bowed, the effect is known as pincushioning or barreling, depending on whether the sides are bowed in or out. To check and adjust horizontal pincushion distortion: 1. Place the monitor so it is facing east or west. Degauss the monitor whenever you change its direction. -
Page 34: Top And Bottom Pincushion Distortion
Adjustments 5. Check for right and left pincushion distortion again. Use the PIN AMP (RV203) control to make the sides linear, if necessary. If one side remains distorted when the other side is linear, follow the steps in the next figure. SIDE PIN BAL ma-0938-89 2.4.4 Top and Bottom Pincushion Distortion To adjust top and bottom pincushion distortion:... - Page 35 Adjustments TOP and BOTTOM PHASE Adjustment (1 of 2) ma-0935-89 TOP and BOTTOM PHASE Adjustment (2 of 2) ma-0937-89 4. Turn the TOP AMP and BOTTOM AMP controls to adjust the lateral line horizontally, as shown.
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Page 36: Checking Horizontal Synchronization
Adjustments TOP and BOTTOM PIN AMP Adjustment ma-0946-89 2.4.5 Checking Horizontal Synchronization To adjust the horizontal frequency: 1. Display the circle-crosshatch screen. 2. Disconnect the green input cable with the BNC connector from the rear of the monitor. The screen should roll vertically and horizontally. 3.