DEC VR297 User manual

VR297ColorMonitor
ServiceGuide
Order Number EK-VR297-SV-001
digital equipment corporation
maynard, massachusetts

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.
The software described in this document is furnished under a license and may be used or
copied only in accordance with the terms of such license.
No responsibility is assumed for the use or reliability of software on equipment that is not
supplied by Digital Equipment Corporation or its affiliated companies.
Copyright © by Digital Equipment Corporation 1989.
All Rights Reserved.
Printed in U.S.A.
The following are trademarks of Digital Equipment Corporation:
DEC DIBOL UNIBUS
DEC/CMS EduSystem VAX
DEC/MMS IAS VAXcluster
DECnet MASSBUS VMS
DECsystem–10 PDP VT
DECSYSTEM–20 PDT
DECUS RSTS
DECwriter RSX


Contents
About This Guide vii
1 Troubleshooting
1.1 BeforeYouStart.................................. 1
1.2 Troubleshooting the Problem . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.1 NoDisplay(1of4).............................. 4
1.2.2 IncorrectColor................................. 8
1.2.3 Purity........................................ 9
1.2.4 Misconvergence ................................ 10
1.2.5 Geometric Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.2.6 Excess Luminance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.2.7 Bright Area at Left Margin . . . . . . . . . . . . . . . . . . . . . . . 13
2 Adjustments
2.1 BeforeYouStart.................................. 15
2.2 Using the Radiance Meter . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.3 ColorAdjustments................................ 18
2.4 Deflection Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.4.1 Vertical Linearity (V-LIN) . . . . . . . . . . . . . . . . . . . . . . . . 21
2.4.2 Vertical Centering, Horizontal Centering, and Screen
Size ......................................... 22
2.4.3 Horizontal Pincushion Distortion . . . . . . . . . . . . . . . . . . . 25
2.4.4 Top and Bottom Pincushion Distortion . . . . . . . . . . . . . . . 26
2.4.5 Checking Horizontal Synchronization . . . . . . . . . . . . . . . 28
2.4.6 Convergence................................... 28
iii

iv Contents
2.4.7 Focus........................................ 30
2.4.7.1 Quadripole Adjustment . . . . . . . . . . . . . . . . . . . . . . . . 31
3 Removing and Replacing FRUs
3.1 Rear Cabinet Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.2 Perforated Metal Shield . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.3 CRTDischarge................................... 34
3.4 Power Supply/G Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.5 LBoard ........................................ 36
3.6 DBoard........................................ 38
3.7 ABoard ........................................ 38
3.8 BBoard ........................................ 40
3.9 CBoard ........................................ 40
3.10 High-Voltage Block (K Board) . . . . . . . . . . . . . . . . . . . . . . . 41
3.11 H-STATControl.................................. 43
3.12 H/J Control Block Assembly . . . . . . . . . . . . . . . . . . . . . . . . . 44
A VR297 Documentation
B Alignment Screens
B.1 Circle-Crosshatch Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . 47
B.2 AllE’sPattern................................... 48
B.3 Color Bars I Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
B.4 Color Bars II Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Figures
3–1 Rear Cabinet Assembly and Perforated Metal Shield . . . . . 33
3–2 AnodeCapRemoval............................... 35
3–3 Power Supply and L Board . . . . . . . . . . . . . . . . . . . . . . . . . 37
3–4 A, B, C, and D Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3–5 High-Voltage Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3–6 H-STATControl.................................. 43
3–7 Bezel .......................................... 44
3–8 H/JControlBlock................................. 45

Contents v
Tables
1 Tools and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii
2 VR297 Recommended Spares List . . . . . . . . . . . . . . . . . . . . viii

AboutThisGuide
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:
Related documentation
Alignment screens
VR297 Color Monitor
The VR297 color monitor has a 432 mm (17-inch), direct-view, antiglare
screen with contrast enhancement. The monitor’s built-in tilt-swivel
assembly lets the user adjust the screen for viewing comfort. When
connected to a host computer system, the monitors can display
information you send to the host system and information the host system
sends to you.
Tools and Equipment
You need the following tools and equipment to service the VR297 video
monitor:
vii

viii About This Guide
Table 1 Tools and Equipment
Tools and Equipment Part Number
Terminal technician tool kit
50 Hz (240 Vac) 29-23270-00
60 Hz (120 Vac) 29-23268-00
Static protection kit 29-26246-00
Safety goggles 29-16141-00
Gloves 29-16146-00
Color video service kit (without power pack) A2-S0099-01
Power packs
90 to 110 Vac, 50 Hz 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
Spares Part Number
Digital Sony
FRUs
A board (video amp) 29-27797 A-1296-461-A
B board (EMI filter) 29-27798 A-1130-505-A
C board (arc suppression) 29-27799 A-1330-733-A
D board (deflection) 29-27800 A-1345-899-A
G board (switching regulator unit) 29-27801 A-1477-873-A
H/J control block assembly 29-27802 A-1477-357-A
K board (high voltage assembly) 29-27804 A-1465-154-A

About This Guide ix
Table 2 (Cont.) VR297 Recommended Spares List
Spares Part Number
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 –
Coaxial cable, video inter. 29-27806 A-1499-495-A
Connector panel assembly 29-27811 A-1429-235-A
D shield 29-27813 4-381-997-01
Main harness 29-27807 1-937-755-11
PCB plastic parts 29-27816 A-1499-498-A
Perforated metal shield 29-27814 4-384-359-01
Pot alignment tool 29-27815 4-382-826-01
Rear cabinet 29-27810 4-381-947-11
Safety covers 29-27812 A-1499-604-A
Screws 29-27818 A-1499-500-A
Tilt-swivel assembly 29-27819 X-4381-961-1

Normally not replaced during field repairs.
Conventions
The following conventions are used in this guide:
Warning Provides information to prevent personal injury.
Caution Provides information to prevent damage to the equipment.
Note Provides general information you should be aware of.
PN Part number.

1
Troubleshooting
This chapter describes how to troubleshoot VR297 monitor problems
by using a set of flowcharts. Each flowchart is for a different type of
problem. The flowcharts guide you through the steps to isolate the cause
of a problem.
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.
The flowcharts instruct you when to perform checks on the monitor,
replace parts, or make adjustments. If you complete all the steps in a
flowchart and the problem still exists, replace the whole monitor.
• If you are going to service a display-quality problem, ask the customer
to let the monitor warm up for at least 20 minutes before you arrive,
if possible.
• Always troubleshoot the most obvious symptom, but remember that
one symptom may indicate multiple failures. The flowcharts assume
that only one assembly has failed or only one problem exists.
1

2Troubleshooting
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. The operator often
has detailed knowledge about the problem.
Identify the Problem
Identify the problem before you remove field replaceable units (FRUs).
For example, the screen display often indicates which problem is
occurring.
Isolate the Problem
After you clearly identify a problem, check the list of problem types at
the beginning of Section 1.2. Select the type that best describes your
problem. Go to the flowchart for that problem. Turn off the power before
disconnecting or replacing any FRU.
WARNING
If you smell burning components, press the monitor power switch
off (O), wait 10 seconds, then disconnect the power cord.
Correct the Problem
Complete all the steps in the troubleshooting flowchart(s) for your
problem. When you are finished, display the host system’s alignment
test patterns to make sure no other problem exists. To display the test
patterns, refer to the host system’s service manual.