Digital Equipment Corporation VR297 Service Manual

VR297ColorMonitorServiceGuideOrder Number EK-VR297-SV-001digital equipment corporationmaynard, massachusetts

2 TroubleshootingNOTEMagnetic fields affect the monitor’s performance and can givea false indication of a monitor failure. Place the monitor awayfrom:•

Troubleshooting 31.2 Troubleshooting the ProblemThis section provides flowcharts for troubleshooting different types ofmonitor problems. The flowcharts

4 Troubleshooting1.2.1 No Display (1 of 4)STARTDISPLAY THE CIRCLE−CROSSHATCH SCREENISTHE POWER NOLED ON THE 3MONITORYES1CRT FILAMENTSSET THE S1 SWITCH

Troubleshooting 5No Display (2 of 4)2TURN OFF POWER, RESEAT THE C BOARDAND CABLES, AND TURN POWER BACK ONARE THE NOCRT FILAMENTS CHECK THE VOLTAGE BET

6 TroubleshootingNo Display (3 of 4)31. TURN OFF POWER2. UNPLUG THE AC POWER CORD3. CHECK THE FUSE ON THE BACK OF THE MONITORIS THE NOFUSE BLOWN CHECK

Troubleshooting 7No Display (4 of 4)5CHECK THE VOLTAGE AT TP9 ON THE A BOARDISTHE VOLTAGE NOGREATER THAN CHECK THE C14 POINT ON THE B BOARD55 VdcYESIS

8 Troubleshooting1.2.2 Incorrect ColorSTARTDISPLAY THE CIRCLE−CROSSHATCH SCREENTHESCREEN MUST MISSINGA COLORBE WHITE. IS THE VERIFY THAT THE PROBLEM I

Troubleshooting 91.2.3 PuritySTARTDISPLAY THE GREEN SCREENISTHE SCREEN NO DEGAUSS THE MONITOR BYTURNING THE POWERSWITCH OFF THEN BACK ONCOMPLETELY ONE

10 Troubleshooting1.2.4 MisconvergenceSTARTDISPLAY THE CIRCLE−CROSSHATCH SCREENADJUST V−CENT TOCENTER THE IMAGE(2.4.2)ADJUST H−STAT AND V−STATTO CORRE

Troubleshooting 111.2.5 Geometric DistortionSTARTDISPLAY THE CIRCLE−CROSSHATCH SCREENMEASURE THE DISTANCE BETWEEN THETOP AND BOTTOM OF THE IMAGE ATSEV

First Edition, September 1989The information in this document is subject to change without notice and should notbe construed as a commitment by Digita

12 Troubleshooting1.2.6 Excess LuminanceSTARTADJUST THE CONTRAST CONTROLTO DETERMINE IF THECIRCLE−CROSSHATCH IMAGEDISPLAY THE CIRCLE−CROSSHATCH SCREEN

Troubleshooting 131.2.7 Bright Area at Left MarginSTARTDISPLAY THE CIRCLE−CROSSHATCH SCREENADJUST THE H−PHASE CONTROLON THE D BOARD (2.4)ISTHE BRIGHT

2AdjustmentsThis chapter shows you how to align the monitor. You do not have toperform every adjustment procedure each time you align the monitor.Howe

Adjustments 152.1 Before You StartLet the monitor warm up for at least 20 minutes before performing anyadjustments on the monitor. The warm-up time en

16 Adjustments2.2 Using the Radiance MeterYou use the radiance meter when making color adjustments (Section 2.3).To use the radiance meter:1. Remove t

Adjustments 172. Connect the ac line adapter to the radiance meter and plug it in to awall outlet.NOTEMake sure that your radiance meter is in calibra

18 Adjustments2.3 Color AdjustmentsNOTEMake color adjustments after replacing the video amplifier board(A board).The following figure shows the location

Adjustments 193. Turn the screen control (G2) clockwise until the screen background isvisible. G2 is the bottom control on the high-voltage block. The

20 Adjustments2.4 Deflection AdjustmentsNOTEYou must perform the deflection adjustments if the deflectionboard (D board) is replaced.This section covers

Adjustments 212.4.1 Vertical Linearity (V-LIN)To check and adjust vertical linearity:1. Display the circle-crosshatch screen.2. Check the pattern to m

ContentsAbout This Guide vii1 Troubleshooting1.1 Before You Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Troubleshoo

22 AdjustmentsV LIN figure 2 ma-0949-89NOTEThe V-LIN BAL control has no effect when the V-LIN control isturned completely counterclockwise (small squar

Adjustments 236. Set the switch S1 on the A board to the test position (up) to produceraster.NOTEThe right edge of the screen may be a purple color. T

24 AdjustmentsVertical and Horizontal Centering Standardma-0947-89Vertical and Horizontal Size Standardma-0945-89

Adjustments 252.4.3 Horizontal Pincushion DistortionWhen the sides of a video display are bowed, the effect is known aspincushioning or barreling, dep

26 Adjustments5. Check for right and left pincushion distortion again. Use the PINAMP (RV203) control to make the sides linear, if necessary.If one si

Adjustments 27TOP and BOTTOM PHASE Adjustment (1 of 2) ma-0935-89TOP and BOTTOM PHASE Adjustment (2 of 2) ma-0937-894. Turn the TOP AMP and BOTTOM AMP

28 AdjustmentsTOP and BOTTOM PIN AMP Adjustment ma-0946-892.4.5 Checking Horizontal SynchronizationTo adjust the horizontal frequency:1. Display the c

iv Contents2.4.7 Focus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302.4.7.1 Quadripole Adjustment . . . . . . . .

Contents vTables1 Tools and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii2 VR297 Recommended Spares List . . . . . . . .

AboutThisGuideThis guide describes how to service your VR297 color monitor in the field.The guide covers the following topics:Troubleshooting the field

viii About This GuideTable 1 Tools and EquipmentTools and Equipment Part NumberTerminal technician tool kit50 Hz (240 Vac) 29-23270-0060 Hz (120 Vac)

About This Guide ixTable 2 (Cont.) VR297 Recommended Spares ListSparesPart NumberDigital SonyL board (convergence) 29-27803 A-1235-011-AH STAT control

1TroubleshootingThis chapter describes how to troubleshoot VR297 monitor problemsby using a set of flowcharts. Each flowchart is for a different type of